Garden School:

Garden School:
Teaching this week: Basic tool fitting - right tool, right size.

Sunday, 19 August 2018

Cherry tree with damaged bark

I had a question come in the other day, about a small ornamental Cherry with damage to the bark - a whole section of the bark at about chest height was peeling away, and the anxious owner was worried that the tree would die.

Here's a picture of the tree, taken earlier this year: as you can see, quite a big area of damage.

So why did this happen, and what can be done?

Well, the first thing to say is that Cherries are not long-lived trees: an ornamental one can have a lifespan as short as 20 years, which is no time at all in the life of a garden, especially if we buy them when they are four or five feet tall, which means they are already five years old before we get them.

So if you have a Cherry that's been there for more than a decade, it may well be heading towards the end of its life anyway.

The actual damage could have occurred for many reasons: it could be frost damage, where water gets inside a small split in the bark, then freezes. As it expands, it splits the bark.

The original split may have been disease: cherries are susceptible to phytopthera and to bacterial infection, and there's not much we, as garden owners, can do about it - the spores are "in the air" as it were, and there is no way to prevent them wafting in.

Canker is another possible cause: if the crack in the bark is accompanied by a gummy substance or a darkened crust, then the tree may be infected with one of the many fungal diseases known collectively as canker. Like phytopthera, cankers are always hanging around looking for an opportunity, and trees that are stressed due to frost damage, mechanical injury or lack of water are more likely to develop canker.

If you spot any heavily cankered branches, the best thing to do is to prune them out, making sure that diseased branches are burned or destroyed, to prevent the disease from spreading right back into the tree, and into others nearby.

Going back to frost damage, a little internet research suggests that after a chilly winter night, the south- and east-facing sides of a cherry tree may split as the morning sun causes the bark to warm, expand and break.  If this occurs, the tree will heal on its own, but it forms callused scabs, which are less than pretty. To prevent this, the internet suggests that we paint the trunk with whitewash to help reflect light, making sure to do this only when the trunk has no open wounds. I'm not sure I'd actually go that far, myself, would you?

Apparently you can also "wrap the tree with plastic, paper or cardboard to keep it warm while it heals."   Personally I would not wrap any living plant in plastic, as it "sweats" which would worsen the problem. And I'm not keen on wrapping any plant in anything, for that matter, because you are creating a bug hotel which may well be ecologically very sound, but is likely to lead to even more damage to the bark. So much for the internet, then!

Another possibility for damaged bark is herbicide Injury: many weedkillers contain a wetting agent that can cause permanent damage in thin-barked trees, such as cherry trees, especially when the trees are young. So if you have to use weedkiller near your trees, try to stay at least 20-30 feet away from the trunk (not always possible, I know), and only ever do it on calm, still days, so that the wind doesn't waft the spray over onto the trees.

If it makes you feel any better, I have this tree near to where I live:

As you can see, the bark is split so dramatically that it's practically hanging off the trunk, and the damage extends well over 50% of the trunk diameter.

Yet it's been like this for at least five years, and so far the tree keeps soldiering on, undaunted, which is probably a lesson to us all in persistence in the face of adversity.

So is there anything we can do to prevent these problems occurring in the first place?

Yes: healthy, stress-free cherry trees are far less likely to succumb to problems such as splitting bark than trees that are poorly taken care of.

If you are thinking of planting a new Cherry tree, wait until early spring: trees planted then will have plenty of time to develop a strong, healthy root system before winter sets in.

Plant them carefully: prepare a good, big hole, make sure it's the right depth, and make sure you don't damage the trunk when you manhandle it into the hole, especially if it's a largeish one.

Be careful with stakes and ties: never, ever nail or screw the tree tie to the tree (don't laugh, I've seen it done), and check the ties every year to make sure they are not getting too tight.

Water and feed your new tree for the first year, and in subsequent years, if we have prolonged dry periods, give it a bucket of water every couple of days.

Be nice to your tree: if it's planted in grass,  make a clear space all around it for a foot or more - grass is terribly competitive for water and nutrients, and both fruit trees and ornamentals dislike having to compete for these essentials.

There's another good reason for making a small "bed" around their base: many bark problems are caused by damage from strimming or mowing, so if you have a small clear area around the base of each tree, it will reduce the risk of banging the mower into the trunk, or of whipping it bare with a strimmer.

So there you go: damaged bark on ornamental cherries can be prevented - to some extent - by keeping the tree healthy and un-stressed: and if the worst does happen, it's not always fatal. Or at least, not straight away!

Friday, 17 August 2018

Hoeing: why I don't do it

The humble Hoe - or, Lethal Weapon and Death To Plants, as I call them.

Many of my friends work in what I call "Estate" gardens: you know,  those big houses owned by rich posh people who have a full-time gardener, or a team of gardeners: and most of them live and die by the hoe, by which I mean that they use them all the time.

But I rarely use one.


Well, firstly, what is a hoe? It's a sharpened blade on the end of a long stick, and you work it by pushing it to and fro just below the surface.

The principle is to chop tiny weed seedlings off before they get started: the dead top part dies in the hot, dry sun, and the root below the surface dies with no leaves to support it.

This only really works on hot dry days, on tiny weed seedlings, with no valuable plants nearby and big gaps between the proper plants: perfect for allotments, in fact, where the crops grow in neat rows, or for the afore-mentioned Estate gardens where they tend to have very large clumps of specific plants, with large gaps between them, making it easy to hoe.

In most of my rather smaller gardens, the beds are packed with a mad variety of plants, in various stages of growth,  and there are no straight lines or obvious gaps at all, such that hoeing is far more likely to chop down something precious than to just get the weeds. Furthermore, most of my gardens don't have those convenient tiny annual weed seedlings: oh no, they have horrible things like bindweed and couch grass, to pick just two at random from the list - and these weeds do not respond favourably to having their heads chopped off. In fact, they see it as "pruning" and they respond by growing even more -  oh woe! So no, I don't hoe. Ho ho. *bits tongue and resists urge to make jolly santa joke*

Hoes come in several different styles: mostly it's a flat-ended blade, but there are also Swoes:

 these are shaped rather like golf clubs and are much better for gardens - as opposed to allotments - as the head is much smaller, and you can, to some extent, work around plants, although they really only work if  you have good big clear gaps between each plant.

This one belongs to a Client, and I do use it for the Rose bed, which has no underplanting at all, so it's much quicker to hoe than to hand-weed: not to mention being able to get in amongst the roses without being scratched to death!

They can also be used, during the June Drop season, for playing Swoe-Apples, a game I invented where you use the swoe rather in the manner of a golf club (with overtones of lacrosse, as you have to hold it in front of yourself) to flick fallen apples off the lawn into the beds, where they can rot down and add organic matter to the soil.. Two points for a clean flick: lose one point for an apple that poings backwards. Beats all that bending down to pick them up!

The second reason I don't hoe (apart from in the rose bed, as mentioned) is that you then have to go round and gather up all the dead chopped tops, otherwise they die on the surface and look horrible. Clients would complain.  Again, in an Estate garden you are working on a large-scale: big clumps of plants, to be seen from a distance, often a considerable distance: so it doesn't matter if there are some dead bits adding to the brownness of the soil, in fact they are probably some kind of lightweight mulch, as far as those beds are concerned.

But in my small gardens, the Client can see every inch of every border: it's a far more intimate experience.

Thirdly, there is the dreaded "pan": this is the technical term for a crust of soil which builds up on or near the surface, which prevents water (rain, irrigation) from soaking in and doing some good. Instead, it sits on the top in flat puddles, then when it dries out, it makes the pan even worse. Frequent hoeing without any sort of digging can lead to this problem.

Fourthly, no matter how good you are with a hoe, there are many occasions where you just can't get the hoe right up to the base of the plane: either there are obstacles, such as low-growing branches (I'm thinking of some particular Roses...) or you dare not risk accidentally chopping the stem. So you end up having to get down on  your knees and hand weed anyway!

At this point, one or two people might be shouting "flame gun!" at the screen: these are long wands with a small blowtorch at the end, powered by either a replaceable gas canister, or a refillable paraffin tank. They are promoted as being an organic alternative to chemicals, for paths and drives. Organic! A complicated,  metal-and-plastic device, using either single-use non-recyclable pressurised cans of gas, or using paraffin (also known as Kerosene) which is a highly toxic fossil fuel derivative which is also used as rocket fuel (look it up yourself, it's evil stuff). Not what I call "organic".

Also, flame guns are notoriously ineffective: they scorch off the top growth, but they don't kill the roots at all, and most weeds/unwanted plants just grow back. Furthermore, their eco-footprint is terrible! And (more to the point) they cost a lot of  money in fuel, as those gas cylinders don't last very long. Not to mention the danger of setting fire to the garden, or to yourself.

So what do I do, if I don't hoe? I use the much-loved Daisy Grubber:

... one simple hand-tool, no moving parts, nothing to break down: they cost just a couple of pounds, and each one lasts for many months.  I dig the weeds out by the roots, while loosening the soil as I go, which I call "fluffing up" the beds, and it gives me the opportunity to check everything as I work around it.

And I know that a weed which I have physically removed is NOT going to grow back!

Thursday, 12 July 2018

Hot Weather Watering: Part 4: Resuscitation

Earlier this week I started a short series on Watering in Hot Weather: the other pages being...

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots

Today, last in the series (unless I think of something else to add), Part 4: Resuscitation.

What to do  if you've left it too long, and the plants are wilting....

In the Garden:

Well, obviously, get out there and water it, even if it appears to be horribly too late: it constantly amazes me how plants will recover from what appears to be certain death.

There's a three-letter acronym they use in the RHS Level 2 course: PWP. It stands for Permanent Wilting Point. (Honest! No joke!)

If a plant has reached PWP then it can't recover, and is dead.

But there is a whole spectrum of conditions before you get to that point - differing degrees of wilting, if you like. So it's always worth watering and waiting, just in case...

You can help by roughing up the surface of the soil around the plants: often, soil will form a pan or crust on top, which prevents any water from getting down to where it can be useful, ie around the roots of the plants. Break up the surface of the soil with a hand-fork or a daisy grubber, aiming to make the top couple of inches penetrable.

If the soil is like concrete, stab downwards with the hand tool, to make vertical holes: they will then fill with water next time you get the hose out, and will act as little sumps, to hold the water down below the surface. Eventually, the sides of all these sumps will soften and crumble, allowing water to penetrate more freely.

Soil pans (or crusts) are often worse where people hoe, rather than weed: a hoe tends to create what looks like a fine tilth, but is actually a shallow layer of dusty soil on top of a hard pan, neither of which is good for the soil or the plants. So if you are in the habit of hoeing, check that your soil is still open and crumbly by trying it with a hand-tool.

With regard to trees and shrubs, they will drop leaves if stressed by lack of water, then grow new ones when water becomes available. So if you find brown, crispy leaves on plants, don't expect them to miraculously turn green again. If the brown or black leaves are willing to drop off when you gently shake them or brush a hand through them, then remove them, rake them up and dispose of them.

But don't pull off dead leaves which are reluctant to fall - don't force them, as you might damage the bud at the base of the leaf, and that's where the new leaf will grow from. Once the new leaf appears, the old one will fall of its own accord.


Next time you are about to water, push your fingers into the soil around the plant(s), if it's loose enough. Is it dry and dusty? Pour on a slosh of water, wait for it to disappear, then push your fingers in again. Is it still dry and dusty, and has the water all gone, leaving the soil miraculously still bone dry?

This is the problem with shop-bought compost: it is very hard to re-wet it.

There are two ways to re-wet compost: either you have to submerge the whole pot in a bucket of water, holding it under until it stops bubbling (resisting the urge to snarl "Give me the secret codes, you swine"), then leave it for at least an hour: or you have to manually push the water into the compost by rubbing it through your hands in the manner of someone rubbing up a crumble.

(For anyone under the age of about 40, or anyone male, much of baking involves mixing fat and flour together. Stirring doesn't do it, you have to get in their with your bare hands and rub them together between fingers and thumb,  using a rub-and-lift action repeatedly, until the mixture resembles fine breadcrumbs.  [At this point, I'm wondering how many people under the ago of about 40, or male, don't even know what fine breadcrumbs look like..]  Wetting compost requires a very similar action, and takes about the same length of time. I'm sure there's a video on it on yootoob somewhere...

... good lord, there is indeed, it's right here.)

So if your pot's soil is like dust, pour on some water and get your hands good and muddy, rubbing the water into the soil until you get mud. Go as far down into the pot as you can - this will depend on how full of roots the pot is. Once the soil is rewetted like this, you will be delighted to see that future waterings no longer flood straight through and out from the bottom.

Soaking is easiest, in the sense that once you plop the pot into water, you just go away and leave it: but it only works with pots small enough to fit into a bucket. And you might have to weigh down the pot, to stop it bobbing around on the surface.

For larger pots, especially heavy terracotta ones, all you can do is place them on the deepest saucers you can find, as per part one:  water them until the saucer fills, give it time for that water to soak back up into the pot, then keep adding more water to the top, until you reach a point where you can water the top without it immediately flooding down into the saucer. This indicates that you have managed to soak at least some of the soil within the pot, hooray!

Leave them sitting in their saucers until the hot weather is gone.... it won't be long, I'm sure.

If you  have a large number of smallish pots: seedlings perhaps, or cuttings, then a soaker box is a good way to do it: take a plastic tray or box or container (or a cardboard box lined with plastic, ie a bin liner, or a compost/bark bag), fill it with a couple of inches of water, and stand the pots in it. Pour more water onto their tops and leave them to soak for a while.

Here's my soaker box at home - left. It's a plastic greengrocers' vegetable tray lined with a compost bag (no expense spared, for us Professional Gardeners!).

As you can see, I use it for individual pots which have dried out too much, and for trays of smaller 9cm pots.

They get plunged, and allowed to soak it all up: and if they are looking a bit pale and wan, I add some liquid seaweed feed to the water in which they are soaking.

The piece of wood top left, in case you are wondering, is a ramp to help my frog get out with dignity... here's a close-up of the top of the picture:

Yup, that's my little froggy pal, the reason why I have snails in my front yard, but no slugs.

Good boy, froggy! He seems to think my soaker box is his own private pond, but I don't know what he thinks about the times when I add the seaweed....

As with the garden advice, I'd suggest not being too quick to prune the plants, unless there are sections which are clearly and obviously dead: if in doubt, give it a chance.

Having said that, with perennials, you can certainly crumple off any paper-dry foliage, as it is unlikely to recover: but in general, I would say leave them for a few days, to see if they pick up.

And finally, don't stop watering just because the sun goes in one day, or if we have a light sprinkling of rain: keep on watering until we get proper, drenching, British-summer-rain again. It won't be long!

If you missed any of the other articles in this series, you can either go back through the archive list, or jump:

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots
4: Resuscitation (this one)

Wednesday, 11 July 2018

Hot Weather Wathering: Part 3: Pots

Earlier this week I started a short series on Watering in Hot Weather: the other pages being...

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots
4: Resuscitation

Today, then - POTS!

Oh la, and fie, and horrors in general: pots in hot weather are Trubble with a capital T.

They are getting all the very worst of drought, for these reasons:

1) they have restricted top openings, so they don't catch any rain that might arrive, and they don't catch much water from random sprinkling either.
2) they don't have access to the water bank in the soil.
3) the sides of the pots get scorched by the sun, drying out the roots.
4) they are usually filled with compost (as opposed to "soil"), which is very hard to re-wet once it dries out.
5) they are frequently left up on their "feet" all through the summer.
6) they are totally reliant on their owner to water them... and they are easily overlooked!

I must just add a word of explanation about watering: in Part One, I went on at length about not flooding any individual plant, and how to move the hose to and fro to give the water time to soak in.

With pots, it's all different: their soil is usually hard and compacted, and they often have a dreadful surface pan, so with pots, it is permissible to flood the top of the pot, then leave it to soak down.

So how can we help our poor pots?

Firstly get them off those feet, and get them standing in saucers: plastic ones, terracotta ones, the deepest ones you can find: or use large trays if you don't have any saucers: and if you are desperate, get a biggish cardboard box (or a plastic tray) and line it with plastic: a bin liner, or a compost/bark bag if they are in reasonable condition. Then sit as many pots as you can fit in, inside it.

Why? If, when you water them, the water runs straight through and out of the bottom: and/or if the soil or compost has shrunk away from the sides of the pot, then your compost has dried out and - as per point 4 - it's very hard to re-wet it.

And pouring more and more water into them doesn't help, because the water runs straight through, without being absorbed.

By putting a saucer or tray underneath the pot, that runaway water will sit at the base of the pot and will gradually, by osmosis, be sucked back up into the pot.

Secondly, try to group your pots together during hot weather: this allows them to form their own little micro-climate. Instead of each pot being fully exposed to hot sun and drying winds, they will shelter and shade each other. Not much, but it might be enough to make a difference: and it makes it a lot easier for you to water them, if they are all in once place.

These two points can easily be incorporated together: move all your pots into plastic-lined trays or boxes!  You could even make a decorative arrangement of them, perhaps with a line of empty pots to hide the front of the box... or some trailing foliage.

But just be aware that you are creating a Slug Hotel, so it's worth checking it every so often, and evicting any interlopers. On the other hand, you are also creating a safe environment for frogs, newts, and other small damp-loving amphibians.

Thirdly, how much to water: take note of the expression "it takes one inch of water on the top of a pot, to penetrate eight inches down". So as most plants have roots of 4-8", you'll need to aim for getting up to an inch or so of water on the top of the pot, as it were. If the water starts to sink into the soil as soon as  you start to pour it on, well, that's good: but you can still see for yourself that you need quite a lot of water to soak the soil to the right depth.

If you are not sure how long it takes to add this much water, stand a shallow straight-sided bowl or container on top of a pot, then water it as much as you would normally do. Look in the pot. Gasp in horror at the bare quarter of an inch of water that has accumulated. Go back and water it properly!

This - incidentally -  is why planting instructions always say "leave a gap of at least an inch between the top of the soil, and the top of the pot."  It's to accommodate the amount of water necessary to properly soak the pot.

If it helps, I hold my hose or watering can over a largeish pot for a count of between 5 and 12, depending on the size of the pot. And that's quite a slow count, but remember that I turn my hose pressure way, way down to avoid jet-blasting.

Those are the three important elements of saving your pots in hot weather: saucers, grouping, and sufficient water.

There are also a few other things you can do,  to help your plants-in-pots.

Clear away any weeds, moss, algae, etc on the top surface. They are cheekily sucking up the best of the water each time.

Rough up the surface: break up that "pan" or crust on top, to make the water more likely to get down inside the soil, rather than running to the edge and sneaking away down the sides of the pot.

Add a mulch of something like gravel, small stones, slate chips, anything like that: a hard mulch prevents weeds, prevents a surface pan forming, and slows down the water that you slosh on top, giving it more of a chance to soak into the soil, rather than running straight through and away. I'm not a big fan of hard mulches on pots, but in hot weather they have a role to play, and many people find them decorative as well.

Finally, remember that pots are totally dependent on you for their water, and in this very hot weather, you might need to water them at least once a day, maybe even twice. It's a small price to pay!

If you missed any of the other articles in this series, you can either go back through the archive list, or jump:

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots (this one)
4: Resuscitation

Tuesday, 10 July 2018

Hot Weather Watering Part 2: don't waste water on plants that don't need it.

Earlier this week I started a short series on Watering in Hot Weather: the other pages being...

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots
4: Resuscitation

Today is Part 2: don't waste water on plants that don't need it.

Not all plants need to be watered!

Look at your beds and borders, and see which ones are showing signs of stress - wilting leaves, yellowing leaves, leaves falling off, and general droopiness. Focus on those one: don't waster water doing a generic "spray everything in sight" policy: one day soon there is going to be a hosepipe ban again, but if we are all sensible and use a little less, that dreaded day can be put off for as long as possible.

Some plants are more susceptible than others: Rudbeckia (Coneflower), for example, wilt at the least sign of drought. As does Lysimachia punctata:

This is what they normally look like, one of my favourite purple-foliage plants (I have been known to shear off the top couple of inches to prevent them from flowering: some people like the bright acid yellow flowers against the dark purple, but personally I can live without them), here forming a river of purple in amongst other planting.

But oh dear, this is what a similar planting is looking like today - right.

Not happy!

Luckily, this is one plant which can recover from drought: I gave it a good watering (and gave the garden owner a polite and tactful talking-to about neglecting their watering despite specific instructions), and if we are both lucky, it will recover: if not, I'll chop off all this foliage, right down to the ground, and wait a week or two for it to throw up a whole new batch of shoots, which they usuallly do.

Campanula (Bellflower) are rather water-sensitive: and Astrantia do exactly the same as the Lysimachia:; they pull a fainting fit, wilt and die, but if cut right back and watered well, they will usually get their act together and re-sprout.

Hydrangea are another plant which you might not consider to be water-sensitive, but they are - very much so. A hot day can see them with their leaves drooping in a pathetic manner, begging for water. Luckily, they will mostly pop up again once they receive a good soaking.

Summer bedding, being short-lived and shallow-rooted, is definitely going to need special attention, and personally I always give roses a good soaking, as they need water in order to produce new shoots, and new shoots means new buds, which means more flowers. So it's well worth giving the rose border some attention.

What about plants which don't need the extra watering?

For a start, ignore the lawn! To keep a lawn green and lush in this sort of weather will require an hour with the sprinkler, and that is just such a waste of expensive tap water: let it go brown and crispy! Unless it is freshly laid turf (in which case, get that sprinkler out and spray, spray, spray!), let it die off: it will recover in an amazing way within a few days of the rains returning.

And they will return, trust me!

Meanwhile, turn your back on the lawn: and Mediterranean plants such as Lavender,  most herbs, anything with silver foliage and/or hairy, furry, mealy foliage - all of these simply don't need watering every day.

So don't waste water on them: give them a drenching maybe once a week, if it continues hot like this, but not every day.

Likewise, established trees and shrubs should not need any help with watering: they have good deep roots, and the soil - thanks to the endless rain of "spring" this year - has a good water bank.

Having said that, anything at all in a pot is going to need special help, so that's the subject for tomorrow's article.

If you missed any of the other articles in this series, you can either go back through the archive list, or jump:

1: General Principles.
2: Don't waste water on plants that don't need it (this one)
3: Pots
4: Resuscitation

Monday, 9 July 2018

Hot weather Watering: Part 1, general principles,

This week, I have had everyone and his dog asking me about watering plants. Hardly surprising, as we've had hot sunshine, hot winds, and no rain for a good four weeks or more, and no sign of the hot weather breaking for at least another week or even longer.

"Phew, what a scorcher!" as they said, back in 76.

I feel sure that in a couple of weeks' time, we'll be shivering indoors, watching the rain on the windows, and wonder if we imagined four whole weeks with constant sunshine, no rain, and no end in sight....but in the meantime, what can we do to help our plants?

I wrote an article about this for GreenPlantSwap the other day, but I have a lot more to say on the subject, so I've split it up into four parts:

1: General Principles.
2: Don't waste water on plants that don't need it
3: Pots
4: Resuscitation

Right, let's start with general principles.

When the weather is hot and dry, you might need to water your plants, and in essence, that means splashing a bit of water on them from time to time.

But as always, there's a little more to it than just a simple bald statement, and as the phrase "hosepipe ban" seems to be hovering in the air, it's worth a few words to encourage us all to use our water wisely.

How to water.

When you water, don't splash it around wildly, all over the foliage, the path, your feet, etc: aim it around the base of the plant That's the bit that needs the water.

Turn down the pressure of the hose, or - better - use a watering can. You are not jet-washing the plants, you are imitating nature, which droppeth like the gentle rain from above.

If you find using watering cans too heavy, and you really have to use a hose, then buy one of those big nozzles with a variety of water patterns, rather than the sort which make a narrow jet.

This is the jet-wash type of nozzle - you twist the yellow part against the grey part to make the spray narrower (and into a jet-washer) or wider (and softer).

There is no pressure control or trigger, it's either on or off: the only way to turn it off is to twist it all the way wider and wider until eventually it stops.

After spraying your legs, and everything within a 180 degree angle...
This type - right - is much better in three important ways.

Firstly, see that big roundy thing at the left? It's a series of spray patterns, you twist it round to select them. The best one is the "gentle rain" setting.

Secondly, see the grey/yellow trigger? That means you point it in the right direction, squeeze the trigger and there is the water, exactly where you want it.

You don't waste water on the journey between one watering point, and another.

The red band going horizontally across is a lock for the trigger, so if you have a large area to water, you can lock the trigger on, to avoid hand strain. Nice!

Thirdly, and best of all, see that red sticky-up tab on top? Push it to the right, you get full pressure. Push it to the left, it reduces the pressure.

So, even if you've turned the tap on too far, you can reduce the pressure down to a point where you are gently watering, not sand-blasting.

Now, a word about those mains taps: don't turn them on full! You don't need to turn the tap on and on and on, until it won't go any further. When I use my own mains tap at home, I turn it from the 12 o'clock position to the 9 o'clock: that's one quarter turn. That's all. And that's plenty of pressure.

Turning the tap on full just puts pressure on every connection in the hosepipe, and much of the time, it means your tap end is dribbling and wasting water. So don't turn it on so far!

Next: how much to water.

Don't pour on so much water that it starts to run away, or makes a big wet puddle on the surface: both of these mean that you have put too much water on too quickly, without giving it time to soak in.

This also means, counter-intuitively, that you have stopped too soon!

Your aim is to give sufficient water that it can soak into the ground around the plant. This means a slower application speed - see above - and it can mean going round the plants in a circuit: instead of doing each plant once and that's it, go to and fro from plant to plant, giving the water time to seep down into the soil before returning.

To explain what I mean, this morning, I watered a long bed of roses for a Client: if you imagine each rose bush has a number, I started at number one, and gave it a slowish count of five. Then on to number two ("..two, three, four, five")

This gives the water time to soak in to number one.

Back to number one (second sloosh), then number two (second sloosh) then on to number three (first sloosh... two, three four, five.)

Back to number one (third sloosh) and now we're up and running: on to number two (third sloosh, two three, four, five) , then number three (second sloosh) then on to number four (first sloosh.)

Back one: number three (third sloosh), number four (second sloosh) and on to number five (first sloosh)

Back one: number four (third sloosh, number five (second sloosh) and on to number 6 (first sloosh)

Hmm, it sounds a lot more complicated than it is!

Basically, once you get going, you water three plants as a group, one, two three: then back one and water three, including a new, dry one, each time. This gives each plant three bouts of watering, with time between for the water to soak in.

A simpler method, on small gardens, is to go from one end to the other, then back again, and back again. (Some of my gardens are quite large, so I've had to establish the most efficient way to do things.)

If you put on too much water at once, you'll often see it forming rivulets and running away. This is a sign that you are watering too fast: water will always take the easiest course - lazy stuff! - and it would rather run away on top, than soak in. This is a particular problem on banks, or beds which have a slope to them.

The answer is to do it more slooooowwllllyyyyyyyy.

You can also build little mini-moats around selected plants, to give the water time to soak in. Of course, they are anti-moats, really: just a ridge of soil, built up on the downward side of the plant, to stop the water galloping off downhill. Technically they are bunds (how many of you know what a bund is? Answers below, please...).


Don't slap on the sprinkler.

Sprinklers are the work of the devil for anything other than lawns, as they waste water by spraying it indiscriminately all over the place, they splatter water all over the foliage, leading to those white water-marks and spots which make people think their plants have a nasty disease, and - worst of all - people tend to set them going and then leave them for an hour or more. Such a waste! Our precious, clean, expensive tap water!

Also, if you use a sprinkler rather than a can or a hose, you miss the opportunity to have a chat, as it were, with all the plants. You miss out on seeing what they are doing, how they are getting on: which ones are flowering, which ones need deadheading, which part of the bed is starting to need weeding, where the gaps are.. all those things that make gardening more interesting.

Watering cans:

The best way - not only are you directing water exactly where it's needed, at a nice slow speed, but it gives you a chance to check out all the plants, as you go along. But I do accept that it can be heavy, and can be slow if you have a lot of plants to water.

You can make things faster and easier by having a dipping tank: this can be nothing more complicated than a large open-topped tub under the tap of the water butt, sufficiently large for you to dip the watering can in. When you are watering, you leave the tap open enough to top it up as you use it.

This cuts out all that tedious standing-around-waiting-for-it-to-fill.

Or, you can get two watering cans and learn to judge how far to turn the water butt tap on, to get the second can full just as  you have finished using the first one.

Handy Hint: (known these days as a Hack, apparently, but I'm that old that I remember when Life Hacks were called Handy Hints, or possible Top Tips) many water butt taps don't put out a neat flow at anything other than fully open, so cut a short length of hose and push it over the tap.

Here's one I made earlier... you might need to hold the end in a  beaker of hot water for 10-15 seconds to soften it, but it's worth it to avoid it splattering all over your hands.

When to water:

There's an urban myth that says it's a waste of time to water in the middle of the day or when it's very hot.

Not true! Well, not entirely true.

The best time to water is very early in the morning, while it is still cool: the water will soak down into the soil straight away, and will be available to the plants as they start their day's work.

Watering last thing is the evening means you are putting water around the roots of the plants while they are "asleep", so they are not benefiting from it: and you are creating a whole mass of five-star hotels for slugs and snails, allowing them to move freely all around your plants overnight, which is their busy period. So watering in the early evening is actually the worst time to water.

Watering in the middle of the day means that the water goes straight where it is needed, and is appreciated straight away. Yes, some of it will be lost to evaporation, but even on the hottest day, most of the water goes where it is needed, and you will see that the soil remains damp on top for some time. If you really, really believe that the sun will suck all the water out of the soil, then after watering, use the hoe to rake some dry, dusty soil over the watered areas, to act as insulation.

As a general rule, then, watering in the morning is best, evening is less good,  but it's far, far better to water in the heat of the day, than to not water at all.

Coming tomorrow:

Part 2: Don't waste water on plants that don't need it
Part 3: Pots
Part 4: Resuscitation

Saturday, 7 July 2018

Salix Kilmarnock: suffering in the heat

A nice lady called Wendy sent me this picture of her Salix Kilmarnock:

...along with the comment that some of the leaves had started to go yellow and drop off and - worryingly - she could see a lot of what looked like tiny black eggs on the undersides of some of the leaves.

First things first, the dropping of the leaves: this is nothing to worry about in early July 2018, after three weeks of solid sun and no rain, with no rain forecast for at least another week.

All it means is that the tree - along with the rest of us - is getting a bit stressed by the continued heat, and is probably a wee bit short of water.

During periods of drought, many trees shed their leaves to conserve water, then when the rains come again, they put out a whole batch of lovely new ones.

So that's the leaves, now what about the things that look like tiny black eggs? Well, they are probably tiny black eggs... *laughs*... and they are probably from aphids. If you have time, they can be removed: either you can jet-blast them off with the hosepipe (a perfectly valid way of cooling down, as there will be a lot of back-splashing, ha!ha!), or you can gently wipe each leaf individually, squashing the eggs and destroying them. It is perfectly permissible to wear gloves to do this.

Whether you manually remove them or not, it is best to give the tree a going-over with the bug spray.

There are two main types: organic ones using “fatty acids” and non-organic systemic ones using chemicals. There is a difference in the way they work, and the way in which they are applied, so it's worth checking which one you have.

Organic bug sprays, using those odd-sounding “fatty acids”, work on contact by smothering the bug. So it's very important to get it all over the plant, including the undersides of the leaves. Yes, I know we all read those instructions, then blithely spray from above - but if you don't wet the entire surface, top and bottom, then you are leaving safe havens for the little buggers bugs to live and breed.

So be prepared to get the spray all up your sleeves, down the back of your neck, and all over the place - but it's worth it, to get rid of the pests.

Non-organic bug sprays are "systemic", which means that they are absorbed by the plant, then when the sap-sucking insects arrive, and bite the plant, they are poisoned. This means that the damage is often done before the bugs die... but it does at least mean that each insect only gets one sip!

Systemic sprays don't need to be applied to every part of the leaf in quite the same way that organic ones do, but you do need to ensure that the leaves are well wetted. And do bear in mind that it takes a day or so for the “poison” to work its way through the plant, hence the instructions on the packs to spray at the first sign of pests - that is, don't leave it until your plant is a heaving mass of aphids before applying it!

And in all cases, read the instructions on the pack, and follow them: they will tell you how to apply it, and when to re-apply it. There is no point spraying the same plant five times in one day - follow the instructions.

Right, that's the dropping leaves, and the aphids: what else is there to mention? Oh yes, take a look at the top of the pot: it seems to have a few weeds and mossy bits growing there. Always best to remove them: a tree in a small pot like this needs all the water and nutrients it can get, so don't make it fight the competition.

Clear out the top layer of soil along with all those weeds, and then add some fresh soil or compost: this is what is called “top dressing”. It's a chance to get rid of weeds along with the tired old top layer of soil. When I top dress, I take the opportunity to drop in a handful of granulated balanced feed such as Growmore, underneath the new layer of soil.

If you don't like the look of bare soil around the base of your potted plant, you can add a mulch of gravel, shingle, stones, slate chips, anything you like: these hard mulches have another advantage, in that they allow the water to soak straight in to the soil when you water it, rather than pouring over the sides of the container.

The disadvantage is that once a year or so, you will need to scrape them all off so that you can top-dress the soil underneath. This is a good time to wash the hard mulch to get rid of moss, algae, lichen etc. You'll usually find that, over time, the mulch becomes incorporated with the top layer of soil, which makes it look untidy, and allows weeds to grow - so it's a good exercise once a year, to clean it all off. It's also a good time to check that nothing has taken up residence in among the hard mulch - they can be a haven for slugs, snails, ants, woodlice, you name it!

Going back to the pot, Wendy's pot is a good shaped one: straight sides are far and away the best, they give the biggest amount of soil and are the most stable.

Second from worst (bear with me!) are pots with wide tops which slope elegantly in at the base, such as this one - left.

They look lovely but as the roots grow downwards, they are in less and less soil: and these pots tend to tip over quite easily. They don't hold as much water as a square-sided one, and have a higher ration of "side" to content, as it were, so the roots get baked by the sun all the way down.

Worst of all are those lovely Ali-baba style pots:

...this one (right) looks lovely, but it combines the top-heavy wrongness of the narrow base with a narrow neck, which makes it impossible to get the plant inside it out, if you need to repot it.

Well, I say "impossible", nothing is impossible, but it took me the best part of a whole morning to wrestle this particular fig out of this exact pot, a few years before this photo was taken, in order to straighten it up.

So, squat and square-ish are the best shapes for a pot in which you are growing a tree, and as always, the larger the better in order to give the tree the most amount of soil, and the best possible "water bank", ie the amount of water that remains in the soil between watering.

Wendy's tree is in a pot that is just about big enough; if it were mine, I would probably get a pot that was a couple of inches bigger all round, but I like to give trees room to stretch a little.

Bearing in mind that these Salix Kilmarnock trees are top-grafted, they won't get any bigger, just stouter: so you might think that by keeping it in a smallish pot, you are restricting its size, but that's not the case. I've written about these trees here, here and here (and several other times! ), so if you want more details about the intricacies of top-grafted Salix Kilmarnocks, check those articles, and you can also use the "search" facility at the top left of the page.

And finally, a general point for all pot-grown trees, we are expecting them to do a lot of work for us, for not much payment: so if you grow a tree in a small pot, remember to give it a feed every few weeks through the summer. Top-dressing in spring, with the addition of a small fistful of granulated feed, will get it going nicely: and add some liquid feed to the watering can from time to time through the summer: I use liquid seaweed, but any liquid feed will be better than nothing.

Oh, one other point:  during a hot, hot spell like the one we're having currently (in a couple of weeks' time, when the clouds come back, and we're sitting indoors glumly looking at the raindrops splashing in the paddling pool we rushed out and bought, we'll no doubt be wondering if we dreamt about five weeks of endless sunshine), you can make life easier for your potted tree by putting a large saucer underneath it: if it's up on feet, take the feet away, and let it sit directly on the saucer.

This means that when you water it, the water will go through the pot and will collect in the saucer, where it can gradually be re-absorbed. This is particularly helpful if you've accidentally allowed the plant to dry out too much: you know that horrible situation where you pour on the water only to see it gallop straight through the pot and out the bottom. By putting the pot on a saucer, that wasted water has a chance to get back inside the pot.

I wrote about re-watering over-dry pots at length here,  so check it out for more details.

Wednesday, 4 July 2018

Practical gardening skills: clipping box topiary

I've been neglecting the blog somewhat, *guilty face* as I have been working super-hard for the last couple of months: not only making hay while the sun has shone, shone, shone, but presenting my usual FSC training courses, including - for the first time - a one-day workshop on the extremely challenging topic of How To Use A Botanical Key.

Not an easy course to run!

I've also been working really hard on Garden School, which is my big project for passing on practical gardening skills. We've been clipping box topiary hedges like mad things:

Here's the Big Knot, half done. Can you see where we've been? *laughs*

Have you ever wanted to have a go at something like this?

Have you ever wandered round all those stately homes, wondering how they get such nice neat edges on their hedges, or how long it takes to clip them? Ever wondered what happens if they slip, and chop off the wrong bit?

Come along to Garden School and find out for yourself!

It's not often that individuals will get a chance to have a go at full-size, mature topiary, but take it from me, it's not rocket science, and almost anyone can do it.

Each session starts with tools (cleaning, maintenance), an explanation of how the plant grows and how we use this knowledge to create the shapes we want: then a demonstration of how to clip, and then you get a chance to do it yourself, including the aftercare of the plants, and how to avoid pesky things like box blight.

The Big Knot is now finished, but of course we'll be doing it all over again in mid September, so if you want to book a place, contact me now for details.

In the meantime, I have a few places left on a very specialist Topiary course: renovation of neglected box hedging. Not for the faint-hearted, this is a chance to see how to restore topiary. There will also be some Box Ball Clipping, which is always fun.

To book a place, or to learn more, contact me at

Wednesday, 11 April 2018

Frost does strange things....

We've had the coldest, most miserable March for years, and four episodes of snow - four!! - over this past winter,  so it's no wonder that a few of the plants in the garden are suffering. We've also had many frosty nights .....

Last week a Client dolefully showed me a large pot of tulips which looked as though someone had held a blowtorch over them: the tips of all the leaves were brown, and the flowering stems were just a line of mush across the surface of the pot.

Frost is responsible for the damage: it causes the water inside the tissues of the plant to freeze and swell up, thus breaking the cell walls. Once they are ruptured, there is no going back, and those cells die.

New leaves are particularly susceptible to this damage, and can be completely ruined, which sometimes means the death of the bulb, as it relies on the spring leaves to build up nutrients to see it through the winter.

Here's a sad example from my own front garden: these are some pots of bulbs, which were too small to plant out and be useful this year, but which I'm growing on in the hopes that next year they will be of flowering size.

The ones on the right are my miniature Red Riding Hood tulip: those on the left (the nice, lush, green ones) are Queen of Night.

As you can see, the Red Riding Hood have all turned brown and mushy, and are definitely not going to survive the experience. The leaves were too small to survive the frost, they are not going to be able to build up their bulbs at all, so they are probably going to die (*sobs quietly*)

The Queen of Night tulips on the left, however, were much larger, and are completely  unscathed.

As a general rule, older leaves can survive snow and frost unharmed, although sometimes a sharp frost will cause them to temporarily wilt:

These daffodils, after a sharp frost a couple of weeks ago, were fine....
...but these ones - right - which were growing less than a yard away from the ones above, were rather less than happy!

Next day, though, they were standing upright again, quite unharmed by the experience.

The buds are a different story: if they are not yet fully formed, frost (and snow, for that matter) won't harm them at all. They seem to have an in-built protection.

However, if the buds are about to open, they will be ruined: turned to mush, brown and nasty, and no chance of recovery. Or of growing a replacement, sadly, and this is what happened for my Client: unfortunately her tulips were just about to flower, and the frost has spoiled them completely.

Even the daffodils are having a tough time of it this year: here are a couple of pots of spare Tete a tete (my second favourite daffodil of all time) which, although known to be a miniature, are not normally quite THIS small:

This phenomenon is caused by frost at the wrong time: a heavy chilling as the flowering stem has just broken the surface of the soil doesn't damage the bud itself, but it causes them to go into a period of dormancy.

Then when it warms up again, they seem to have had their clocks re-set, rather like the way a power cut causes my central heating to come on at odd times of the middle of the night (memo to self, really should remember to check it after a power cut).

With bulbs, it's the other way round - instead of being "late", they think that they have already done all the growing that they need to do, and go straight on to opening the flowers.

And you can see that several of the leaf tips are very pale greeny-yellow, indicating the frost damage.

Is there anything we can do? Well, not really: I'll give these daffodils a good liquid feed every couple of weeks, and hopefully next year they'll come up at the normal size.

As for those Red Riding Hood tulips.. well, both my Client and I will probably have to resign ourselves to losing them.

Saturday, 31 March 2018

Permaculture, Forest Gardening, Square Foot Gardens

Recently, a friend of mine ("Hi, Katie!" *waves*) sent me a link to this quite incredible story on a blog in America: the headline reads "Permaculture Garden Produces 7000 Pounds of Organic Food Per Year on a Tenth of an Acre" 

Is that weight or money? Oh, it's America, must be weight. That's just over 3 metric tonnes, or 3½ American tons, of food.

Here's what it looks like:

 Well, that is pretty awesome, I have to say.

The story (which you should read for yourselves - go on, follow that link and check it out, it's quite short) tells of a chap living in downtown Los Angeles, who got fed up with the money, time and water he spent on his lawn, and decided to rip it out and grow veg instead.

They now proudly claim that it's producing 90% of their vegetarian diet, plus they sell $20,000 of plants each year, so it gives them an income as well. And they don't use any artificial fertilisers at all.

OK, so far, so lovely.

And it is lovely: it's a great story, and it is something that should inspire us all to have a go. The daughters of the guy who started it say "he took over every square inch, horizontal, vertical, the frontyard, the backyard and the driveway".

But there are a couple of caveats that I would like to mention.

Firstly, Los Angeles.  The climate there is somewhat different from ours in the UK. Note the lack of any sort of greenhouses - they just don't need them. Their idea of winter is 20 degrees C (dropping down as much as 10 degrees overnight, ooh!), so as far as we are concerned, it's summer all year round.

Secondly, looking after this garden is going to be a full time job. Don't imagine that you could just potter around for half an hour each evening. This is intensive farming.

"Everything is done by hand," they say - there isn't room to hoe, because the plants are so densely packed, which in principle, means that there is no room for weeds, but we all know how well that works out, don't we..... and we have to assume that they are picking the bugs off by hand, constantly, as well. No chemicals, remember?

They make a big deal out of how they don't deplete the earth in the way that modern farming does: they aim (as any sensible gardener does) to increase the fertility of the soil by constantly adding organic matter, and by the use of deep no-dig beds, and one of their philosophies is to ensure the soil is covered with foliage at all times:  no bare soil there! They get, on average, no rain at all there between May and September, by the way, hence their emphasis on avoiding water loss through evaporation. But no matter what they call it (and they, apparently, hate the word Permaculture, denying that it's built on Permaculture principles at all), it is intensive farming.

Thirdly, this is a dry, dry climate: in the UK, if you crammed plants together like that, you'd have mould, mildew, slugs, and snails to contend with.

Fourthly: preparation, preparation, preparation. The article tells us that they spent from 1999 to 2007 improving the soil: now that's what I call preparation. They say that it was pretty much the poorest soil you can get, when they started, but still, eight years!! But that's what you need to do if you want to farm as intensively as this: the soil has to be absolutely top notch before you even start.

Fifthly (still not sure if that is a real word), presumably they have to watch the place like hawks night and day to prevent incursions from animals, thieves and vandals. The concept of turning your front garden and drive over to growing plants is an excellent one, but you do have to consider the neighbourhood, the wildlife, and the risk of damage, theft, and/or contamination.

I hardly need mention the danger of such intensive cultivation with regard to pests and diseases: one vine weevil in there, one butterfly laying eggs, one tiny speck of disease, and the entire garden could be infected within days. With no gaps between anything, it would be impossible to stop it spreading all over a bed, and then from bed to bed.

They also produce 2,000 eggs a year - that's probably ten birds: I can't see from the photos where the hens are kept, but I imagine they have to be firmly penned in to keep them out of the food beds.

So that's me, pointing out some of the negative aspects of this article, as far as we in the UK are concerned.

But what good points could we take from it?

Well, for a start: who needs a great big lawn in front of their house? I'm not a big fan of lawns, I don't have any in my own (very small) garden, and I am all in favour of turning them over to something more useful: as long as it is fenced and protected, and as long as you don't fall out with your neighbours, who might think that your veggies will lower the resale price of their house. As anyone who has grown veg will know, for most of the year, it ain't pretty!

This - right - is two-thirds of my own front garden, turned over entirely to shingle, with plants for sale: everything you can see is in a pot, and everything is available for sale. Or was, last year! There's a different selection now.... but this shows what you can do with even a very small garden.

Then there's the Forest Gardening aspect: don't be restricted by not having much ground in which to grow: think layers, think vertical, use all those garage walls... and garages usually have gutters, so there's an instant source of water for irrigation.

They mention Square Foot gardening, and if you have never heard of this, google it now: it's an interesting idea, well suited to our small UK gardens, and is something that can be gradually increased.

So what am I actually saying? I'm saying, don't look at this guy's garden and imagine that you could get the same results in five minutes: instead, read about what he did and how he did it: do some research of your own: look at your own garden with a view to seeing what areas you would be prepared to turn over to veg: and think about how much time you have available to tend such an area.

Then get out there, and do it!

Thursday, 29 March 2018

Festuca glauca - small blue clumping grasses: to trim, or not to trim?

This is a question which vexes me on a regular basis: several of "my" gardens have these small rounded decorative grasses, and every year in autumn, I have to decide how to manage them over the winter.

My standard method is to rake out all the dead grass, using my faithful daisy grubber and/or my gloved hands.

Gloved? Always gloved, when dealing with grasses, as  you never know when they are going to give you a sly paper cut.

It's like combing out the tangles in your hair: you keep on combing until the daisy grubber runs through with no resistance, no matter what angle you use. Then you know you have truly removed all the dead stuff.

But then, there is the question of what to do with what is left. Often the clumps look a bit lanky and scruffy, and the garden owners often ask me to trim them, or "clip" them, so that they look neat over the winter.

I'm never happy doing this, because I think that the beauty of these small grasses  lies in their loose outline: if  you clip them, they turn into topiary and then you have to keep on clipping them, otherwise they look strange when they start to regrow.

It's important to  understand, at this point, the manner in which grasses grow.

Most garden plants grow from the tip onwards: if you cut them - as we do with Box and Yew, to make topiary and hedging, for example - then the cut end will immediately sprout new growth, often they branch out and become thicker. This is how hedges become dense.  This is also the basis of the Chelsea Chop: we cut off the single stem, which then re-grows, usually with multiple new stems.

Grasses, however, grow from the base: new leaves sprout from the centre of the clump.  They grow in rather the same way that our hair does, ie from the root: when we cut it, it continues to grow but the cut end remains cut: the hair is pushed out from the scalp, and the new growth is right there down by the roots,  not up by the tip.

So when we cut the blades of a decorative grass, we lose the tapered point and end up with a blunt tip. This blunt tip does not stop the grass from growing, but it will never regrow into a delicate point, it will always be blunt. This, in my opinion, rather spoils the look of the grass.

In addition, and again, rather like our own hair, each blade of grass will grow for a certain time, then it will stop growing, and in time it will be replaced by a new one growing from the base. So, those cut ends might "move outwards" for a while, or they might sit there, stationary, until they die.

New blades appear in a continual process: faster in spring and early summer, slower in autumn, and not moving very much at all through the winter.

This means that as soon as you clip or trim a clump, no matter where you cut them, new tips will appear in a week or two, because there are always some new shoots on their way up through the clump.

But does this matter? How long does it take to re-grow?

Aha! Time for some citizen science, let's do an experiment.

This garden has, conveniently, two identical Festuca glauca plants, side by side. So they get the same light and water conditions, they are in the same soil, they were planted at the same time (which I happen to know, because I supplied them) and they were the same size when planted.


Here we are in July. They were looking rather brown and battered (sorry, I forgot to take a "before" picture), so I raked them both thoroughly, removing all the dead stuff, which freshens them up, removes several handfuls of what I call "bug hotel", and reveals their nice blue-ness again.

Then I trimmed one of them "to make it neat".

As you can see.

Exactly four weeks later, late August, you can see that the trimmed one has sent out a few wispy bits, which are the new blades of grass "growing out" through the haircut.

It doesn't look too bad.

The  uncut one has filled out, and is again a pleasing dome of foliage.

Here we are again, another two months on: you can see that the chopped one has now more or less regained the proper shape.

But it is still lagging behind in terms of size - it's distinctly smaller.

Both of them are starting to go a bit brown, as we are now well in to autumn.

Here we are again the following spring, not the best of pictures: the one which was cut is still slightly smaller-looking that the uncut one, but it has at least recovered the fluffy shape.

So do we have a conclusion?

Trimming decorative grasses ruins the shape, in the short term, unless you particularly want the sheep-sheared look.

There is no horticultural justification for clipping them, other than "to make them look neat".

It's far better to just rake out the dead matter once or twice a year.

But, at the end of the day, if the owner wants them clipped, then I will clip them!

Saturday, 24 March 2018

What to do with an over-pruned weeping Silver Birch

Here's a picture that could just as well be titled - well, I can't quite think of the right title for it.

 *pause while I hoot hysterically and wipe away a tear of laughter*

The new owners of this tree contacted me today, asking for advice on how to prune it: they correctly spotted that the top *pauses to wipe away more tears and blow nose* is full of dead material which needs to be cleared out, and they commented that is it far from  graceful.

They also point out that because it is right on the corner of two paths, it can't be allowed to weep properly (unlike me, still wiping away tears) as the growth is all at head height.

It has clearly been massacred pruned like this to allow people to walk underneath it, and judging by the thickness of the thatch, and the stoutness of the trunk, it's been done, year on year, for quite some time.

Right, first things first, what is it:  it's a Silver Birch. I can't tell which one: it could be Betula utilis 'Pendula' (although the bark doesn't quite look white enough), it is more likely to be Betula pendula, possibly 'Youngii' or 'Tristis' but both of those would normally be a little higher in the trunk: so I suspect that this is a top-worked tree.

That means that it has been grafted, just like the dear little Salix Kilmarnocks of whom I have written here, here and here. (*laughs*) (I'm laughing because I sound like an air hostess pointing out the emergency exits.) This means that it is never going to grow any higher - those branches are always going to start at that height, and they are always going to grow downwards, so they are always going to be in the way.

Secondly, it is very clearly in the wrong place. No doubt when it was planted, it was a dear little thing, with a skinny trunk and not very many branches, and it was probably thought to be well clear of the paths. However, they didn't take note of what is called "eventual spread", so they didn't take into account how much bigger it was going to get. In fact, I imagine that they were told by the supplier that, being a grafted tree, it would not get any bigger. They should have been told "it won't get any higher, but it will get wider."

Thirdly, it would be possible to get up a ladder and painstakingly remove all the dead branches, which would at least have the benefit of reducing the "Tonga Beach Hut" effect, but it would never regain it's true weeping form, bearing in mind that as soon as it started to re-grow, the new branches would be interfering with passers by again, and would have to be cut back again.

The only solution here, I'm afraid to say, is to chop the bloody thing down. I'm wiping away a non-hysterically-laughing tear at this point, as I hate to see a tree cut down at any time, and I'm particularly fond of Silver Birch, but in all honesty I can't see any way of "managing" this tree that would be comfortable for walkers, nice to look at, and in any way pleasing to the tree.

Cut it down.

Get the tree guys to cut it to ground level and grind out the stump. Fill it with soil, add some grass seed, and by mid summer it should be nothing but a memory.

It would be worth the new owners taking a look at the situation once the tree is gone: why was it planted there in the first place? Was it to stop people cutting over the corner of the grass? In which case, they could plant a small bushy shrub there instead.

Was it to give shade, or to block off an unwanted view looking outwards from the house? If so, plant another tree but position it a lot further inside the grass area - you can see that the trunk is in the centre of a circle of foliage, so measure the circle and then work out how much further away from both paths the trunk needs to be, in order for the foliage to not come into conflict with the paths.

As "chop the bloody thing down" is a bit of drastic solution, I would like you to know that I have given this matter some considerable thought, and I really think it's the best thing to do. However, I did come up with three alternatives:

1) cut the trunk at waist height, and use it as a small table. 
2) cut it at knee height and use it as a seat.
3) cut it straight across the trunk, just below where all those branches sprout out. This would remove the top-worked, "weeping" material and would leave a stout trunk, which is the original Betula tree - probably, from the bark, Betula pendula.

(It's important to point out that Betula pendula, despite the name, is is NOT necessarily a weeping tree: the branches are slender and often drooping, but not weeping like a weeping willow. To get that effect, you have to buy a particular cultivar, or a top-worked one.)

By chopping off all the grafted material, you would be left with, in effect, a pollarded "normal" Silver Birch tree, which would - possibly - re-grow into a multi-stemmed upright tree. This would not interfere with walkers on the path, but it would then become a substantial tree: you can see by the thickness of the trunk that it's a well-rooted, mature tree, and if the rootstock were allowed to re-grow, it might well turn out to be 30-50' tall in time. And it is quite close to the house.

So on balance: sorry, everyone, but my recommendation is to remove the poor thing.

Monday, 19 March 2018

Vine Weevils and what to do about them

A question came in yesterday, concerning the dreaded vine weevils. Before I get to the actual question, here's a bit of background.

What are they, and why are they dreaded?

Well, they are a small, crawling insect which eats the leaves of plants, then lays eggs on the soil around the plant. These eggs hatch into nasty, greedy, little grubs which eat the roots. This causes the plant to die. And this is why we hate them so much.

They have a real taste for plants in pots: you do find them "loose" in the garden, but not that often - however, most people with plants in pots will, at some point, find they have an infestation of vine weevil.

So, Know Thine Enemy.  Here's a picture of the little blighter:

Note the ribbed appearance of the back end, which is usually black but can have splotches of buff/brown/orange: note the jointed carapace, the snouty snout, the long probing bits, the sharply-angled legs.

This is a female - they are all female - and they are born ready fertilised, so they start laying eggs as soon as they are adult.

The eggs are tiny things, they hatch out into:

... these nasty C-shaped grubs. Creamy white colour, note the brown head-cap.

All the books will say C-shaped, by the way, but it useful to know that they sometimes appear to be quite straight. Poking them will usually make them curl into the C shape, though.  These are the ones that do the damage to the roots.

The C-shaped grubs eventually pupate, so sometimes you find these weird things (left): they have lost the brown cap, and have developed rudimentary legs and snouts.

I always think they look a bit like chess pieces at this stage. If you find them, they are still moving, but slowly.

This is the damage which the adults do: "notched leaves".  They sit on the edge of the leaf and chomp out a big piece.

Can be confused with the damage caused by leaf-cutter bees: but the bees do a very neat circular hole, very regular: vine weevils make ragged notches.

Why are they such a problem? Because those grubs will devastate plants in pots: they will eat and eat and eat until the roots are all gone. If you don't spot them, they pupate, hatch, and lay more eggs. Thus the cycle continues, and once you have them, they are very hard to eradicate.

How do you get them?

Usually, they are brought into a garden on an infected plant. Often, regretfully, bought from an otherwise respectable garden centre or nursery... who are the very people best equipped to spot them, and - as plants are their "product" - who should be obliged to ensure that all plants are weevil-free.  However, they are not, and this is why, in a perfect world, we would keep new plants in a quarantine area until we are sure they are not infected with not just weevils, but any other creepy crawley and/or disease.

Of course, in a perfect world, the garden centres and nurseries would do their job properly and ensure the plants are not infected....

Vine weevils can't fly (thank the lord!) but they are very good climbers, and tireless walkers, so in a garden centre or nursery, where the plants are all crammed together in pots, they quickly spread and infect the entire place.  Then, when you innocently bring an infected pot home, they quickly spread to all your other pots, curse them.

How to spot them:

The obvious sign is the notches leaves where the adults have been feeding, but that's not always visible: you could have a pot which  is heaving with grubs, or has just had eggs laid in it, but on which there are no longer any adults, so you won't see any damaged foliage.

Usually, the first people know about it is when the plants start to die. Or if you go to move a plant, and rather lazily pick it up by the plant instead of by the pot (be honest, we've all done it!) and the plant comes off in your hand, leaving the pot and the soil (and the shattered remnants of the roots) behind.

When you tip out the pot, you will either find little air pockets, usually containing a grub, right up against the side of the pot: or, if you shake the plant to loosen the soil, you'll find the white grubs falling out from the centre of the rootball.

What to do:

As soon as you find the first sign - the first notch, the first rootless plant, the first time you tip out a pot and find grubs - you must take action.

Check every pot that you have. Every single one! If you have small pots, or plastic/terracotta ones up to about 3litres, here is the regime:

1) Move them all to one end of the patio, so you can go through them methodically, one at a time.

2) Shake them upside down over a tray, or over a hard path (concrete or tarmac) to see if any adults fall out of the plant. Any that you find, crush mercilessly with your boot, or cut in half with scissors/secateurs.

3) De-pot: turn the pot upside down, knock the plant out of the pot, and check the rootball. If you see white grubs, put it to one side, on the "infected" pile. Feel free to kill any and every white grub that you find: you can squish them by hand - it's ok to wear gloves - you can crush them with the back of the trowel (be warned, they squirt), you can chop them in half with scissors/secateurs/knife, you can drop them into a jar of salty water and leave them to drown (takes days, and when would you be sure?) you can even put them out for the birds, but only if you put them in a dish that they can't climb out of.

4) If you don't see grubs on the outside, pull the plant fairly firmly, to see if it is still properly rooted. If the plant appears to be firmly rooted, put it back in the pot and put in the "probably ok but we'll check again later" pile.

5) If it "gives" at all, then take the pot to a potting bench or tray, and shake off the soil until you can see the roots clearly. Any white grubs, put it in the "infected" pile. If none, wash the remaining soil off the roots by dunking the plant into a bucket of water and swishing it about. This plant is now clear - no adults, no grubs, no eggs - so it can be potted up again, using clean fresh compost. Discard the compost/soil that  you removed: don't put in on the compost heap, as this just spreads them all round your garden: instead,  put in your council wheelie-bin for garden waste if you have one, and if not, collect it all and take it to the tip.

6) Having worked through all your pots, look at how many were found to be infected: if it's only a few, then the "probably ok" ones can be returned to the patio display. If there are a lot of infected ones, then go back to the "probably" pile and go through stage 5 for each one: de-pot, shake off the soil, wash off the soil, repot in clean compost, dispose of the soil.

As for the "infected" ones, go through stage 5 with them but if, when you shake off the soil, there are hardly any roots left, the throw the plant away: unless it is really precious to you, there is no point wasting a year trying to revive it, it is better to go out and buy new ones.

And if you do, don't forget to check them all before you bring them back into your freshly de-contaminated garden: do stages 2, 3 and 4, preferably before you get to the tills.

If you ever find vine weevils or grubs in plants at a nursery or a garden centre, take it straight to customer service and demand to see the manager. Tell all your friends not to shop there, until you are certain that they have dealt with the problem.

"But I have really big pots."

If you have large pots, such that you can't tip them upside down, then spread an old sheet around the base of the plant, and vigorously shake the foliage, ruffling it with your hands, to see if any adults fall out.

Then, see if you can dig around the base of the plant: if the soil is compacted or full of roots, then you won't be able to do a physical check, so your only option is to go for chemical or biological warfare.

Chemical warfare: There are products you can buy to kill the grubs: you dilute it, water it on, and after several weeks it will have killed any grubs. Follow the instructions very carefully, especially in relation to time of year/temperature.

Biological warfare: You buy a pack of live organisms which you water onto the soil: these organisms find their way into the grub, where they replicate and kill the grubs. They can be incredibly effective, BUT they can sometimes be completely ineffective.

Why the difference? If you read the instructions and follow them, only applying the nematodes at the right time of year, within the right temperature range, and before they die, then they will kill all the grubs. It all goes wrong if you keep the pack for too long before using it: or if you apply them at the wrong time of year, or when it's too cold.

Additionally, they don't kill the adults or the eggs, so you will have to apply them again - in spring, and again in autumn, as per the instructions on the pack -  in order to break the cycle.

So, let's get onto Sue's problem: she wrote to me, saying that she found notched leaves for the first time in her garden last year, then found adults, so she applied nematodes in autumn. This spring ("Spring? Have you seen the snow outside??!") she de-potted a rose, planning to plant it out in the garden, only to discover grubs in it.  The question was, is there any way of getting rid of these things for once and for all.

The answer for Sue and anyone else with the same problem is yes - but it will take a bit of work.  Having gone through all your pots and shaken out the adults, shaken out/washed off the grubs and eggs, repotted everything and applied chemicals and/or nematodes as you saw fit, you then have to do the following:

1) Constant vigilance. Once you have an infestation of vine weevil, you have to be continually on the lookout for them. Inspect leaves every week for damage, gently tug on potted plants to ensure they are still firmly rooted, and once or twice a  year, go through all your pots and de-pot the plants to check their rootballs.   This is a good thing to do anyway, as it gives you a chance to see if they are becoming rootbound, or are too dry/too wet etc.  Go out after dusk with a torch, as that is when the adults are likely to be walking around.

2) Be harsh: if you find infected plants, if you cannot be bothered to completely remove ALL of the soil by shaking, and by washing it off, then you must discard infected plants and buy new ones.

3) Always check new plants very carefully, and if possible, quarantine them for a few weeks so you can check up on them before introducing them to your garden.

4) Consider raising your pots onto benches or stands, and applying grease bands to the legs: this is sticky stuff, rather like flypaper but on a roll, which you wrap around the trunks of trees to catch all the non-flying bugs. It works just as well on bench legs, although it's a horrible fiddly, sticky job to get them in place. But, if you are desperate, it's worth doing for a year, to break the cycle of adults-eggs-grubs-pupae-adults.

So there you have it, vine weevils in a nutshell (horrible mental image, why did I say that?): if you get them, it's probably not your fault, but to get rid of them takes constant vigilance and a degree of persistence - but it can be done!