Garden School:


Garden School:
Teaching this week: "Putting the garden to bed for the winter"

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.

Pots:

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...).

Sprinklers:

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 Inquiries@rachel-the-gardener.co.uk.