Garden School:

Garden School:
Suspended for now - instead we'll have C-19 Garden Questions!

Saturday, 30 May 2020

Bramble Removal: turning brambles into a meadow

I had a comment from Martin the other day, on one of my many posts about brambles (*waves to Martin*) and it raised a couple of good points, so I'm starting a new article for it. (That original one is now a mile long, and I do wonder if anyone actually ploughs through all the comments!)

Martin said:

"Having now got everything down to ground level it's obvious that the bramble & nettle infestation has impoverished the (light/sandy) soil to the extent that there's a lot of moss (now dry) cover over a large area and little evidence of grass.

"Do we just wait for the rain to see what appears?"

Firstly, well done Martin! If you can see bare soil, then you have done a proper job! 

As for the mossy, impoverished soil,  that will be because brambles are greedy swines, and will also have shaded the ground, which promotes moss formation.

However, all is not lost: nettles have a reputation for being able to access nutrients well below the surface of the soil, with their long yellow roots. They are often used as an indicator that the underlying soil is quite good, even though it might look quite poor on top.

So, what would I suggest? Bearing in mind that I haven't seen it... I would suggest raking off the moss - it does no good, it doesn't rot down and enrich the soil in any way, and it will be full of moss spores, so if you leave it, you will just get more moss.

So if it's all nice and dry, rake it together into big heaps and burn it!! OK, you could choose to bag it up and bin it, or take it down the tip, but it is usually very bulky stuff, so it takes up a lot of room in the wheelie bin or in your car. If you burn it, it destroys the spores, saves you a trip to the dump, and you can rake the ashes out over the soil, where any nutrients will be given back. Hooray!

What will that leave? An area of light, sandy soil, with very little growing on it. (And possibly one scorched patch where you had the bonfire, but don't worry about that...)

Perfect for making a meadow!

When people try to create a wildflower meadow from a grassy area, the usual problem is that the soil is too rich, and the grass is too dense and too strong, so wildflower seeds - and I assume, Martin, that when you say "meadow" you mean "wildflower meadow" - struggle to gain a foothold.

This means that if you have bare, impoverished, sandy soil with a sparse amount of grass, it should be perfect for scattering seed and getting a lovely meadow going.

As it has been unseasonably dry and sunny, with no end in sight, I would hold off scattering your wildflower seed until it rains, because if you do it while the soil is bone dry, the little birdies will come and scoff the lot. And the small mammals will grab any which the birds miss.

The act of raking off the moss will "fluff  up" the top surface, which is probably pretty dusty and light anyway, so if you wait until it rains, or is just about to rain, the rain will push the seeds down into the soil, and they will germinate quickly: and once they have germinated, the small plants will be less  desirable for hungry birds.

Hope this helps!

Thursday, 28 May 2020

The importance of labelling plants correctly.

I have a tray full of pots of large Bearded Iris in my front yard: they were given to me two years ago, when a friend said she was digging up her beautiful white Iris and binning them.

Being one who cannot ignore a plant in distress, let alone a sad little orphan who is about to be thrown out, I brought them home and potted them up.

Did I label them?

Yes I did. The tray contains seven large plastic pots, now getting all contorted as the Iris inside them grow and grow... they didn't flower last year, which was understandable, as Iris don't enjoy being ripped out of the ground wherein they have lain for so long..... it usually takes them a year or two to recover.

This year, cheers and applause, flowering stems popped up in five of the seven pots.

Gleefully I waited for the flowers to form....

Hang on!

That's not white!!

Sure enough, two of the pots sent up lovely dark blue flowers.

However, lovely they may be, but they are not white, so out they go: labels changed to "blue", and into the For Sale section.

Tearing of hair!

So then I had to wait, on tenterhooks, for the other pots to flower.  Would they be blue as well? Would they be white? Where had all the white ones gone? Had I accidentally sold the white ones, mis-labelled as something other than white?

Oh no!

A week later, much to my relief, two of the other pots sent up white flowers, and they are truly gorgeous.  No sign of flowers on the remaining pots, all of which are still labelled "white" but now with a question mark on them.

And that, dear readers, is today's lesson: always, always label your cuttings, seeds, and rescued plant material as soon as you can!!

Saturday, 16 May 2020

How to even up a medium sized Japanese Maple

Funny, having very recently written about my exploits, tidying up a small Acer palmatum, I have now received a question from Donna in Rhode Island, asking about her rather lovely Japanese Maple, which is a bit uneven.

 Donna says:

"I have a few long branches which seem to have been cut before I bought it and new, smaller branches trying to reassert themselves in the same direction trying to grow parallel with the old."

This is a very common problem: the nurseries know that people want to buy a good-sized tree (or shrub) but they don't want it so big that they can't get it in their car.

The answer, alas, is for the nursery to chop bits off, in order to keep the tree or shrub down to a manageable height, with no thought for how it is going to grow for the rest of its life.

It's very common for plants to respond to pruning by sending out a spurt or clump of new shoots from the point where they were cut: this is often an excellent thing, if you want a hedge, or if you want a multi-stemmed tree, but not so good if you are looking for a more traditional "tree" shape.

Especially for these Japanese Maples, which are supposed, if anything, to have sinuous and interesting trunks, not a stick with a tuft of foliage on top.

(I'm not saying that Donna's tree is a stick with a tuft of foliage, no sir, not at all!)

Here's a couple of photos to illustrate this phenomenon:

They are photos of a particular Portugese Laurel (Prunus lusitanica), which regularly outgrows the space in which it is planted. Every year, the owner asks me to reduce it in height, but not to remove any of the width, because it is screening something ugly. So instead of the usual "rule of three" pruning technique, I have to do what I call "lollipopping" which is where you just chop a bit off the top, to bring it down to a reasonable height.

(Not a technique I enjoy using, but in some circumstances, I do what I have to do!)

Now, every time I do this, the cut end sprouts a few new shoots. So, the next time I do it, I cut the original single branch, an inch or two  lower than where I cut it last time.

Why? you ask.

Well, let's say it's Year One, and there are seven upright stems which are too tall. I cut them all - that's seven stems, all cut to say 6' high,as per the Client's request.

For the rest of the year, they grow merrily, each one putting out three or four shoots.

Now it's Year Two, and those multiple new shoots - 7 x 3 or 4 - are now too high again. If I were to cut each of them, that would leave me with up to 28 shoots, all about three inches higher than my original 6' cut.

They all grow merrily, again, each one putting out three or four shoots.

So in Year Three, oh dear, we have 28 x 3 or 4 shoots, and now our small shrub is looking rather top heavy - bare down below, and a great big tuft of foliage up the top. The over-heavy top foliage keeps the light away from the lower branches, so they tend to get less and less well clothed.

And now I have to reach up to 6'6" in order to cut them, and I'm only 5' 6" myself.  (Actually, I'm five foot five and three quarters, it's  my ambition to be five foot six. Apparently we stop growing upwards as we get older, and start to actually shrink. I'm not sure if I'm sufficiently aged to start shrinking - although I have felt like it in the past few months!)

So you get the point: the shrub is growing higher, and I am not. Eventually I have to start standing on steps in order to cut it each year, and the Client eventually notices that it's growing too high.

All this palaver can be avoided by simply cutting a little bit BELOW your last-year's cut.

Here's a picture of the one I did last week:

Here you can see that just above my cut, the stem branches into three.

Those are the new shoots from last season, which grew in response to me cutting it, just where the fork occurs.

If I were to cut each of them, I would have three times three shoots next year.

Aagh, panic! That would be bad.

Here's another branch from the same shrub: again, I have cut it just below my last year's cut, and you can see that this one has four big stems shooting from the cut (there's one round the back), and a couple of little ones as well.

So, getting back to Donna's question, when the nursery chop a bit off a tree or shrub, the tree often responds by throwing out several new shoots from the cut end.

Sometimes, this is a desirable thing: it's how you get multi-stemmed trees, for a start!

But in other cases, it leaves the tree -  in this case - with what is called "multiple leaders", so instead of having the traditional single trunk or leader, Donna's tree is developing two or more of them, at the same time.

All is not lost: if Donna wants the tree to grow taller, in a traditional single-trunked shape, then she will have to select the smaller of the two parallel upright leaders, and cut it off.

This is to leave the tree with only one leader, so that it will concentrate on becoming a tree. Sometimes this will leave the tree horribly lop-sided, in which case the remaining stem might need a bit of a help, ie a stout cane that it can be tied to, in order to force it back into a fully upright position.

But you would be surprised how trees will straighten themselves up, if a lot of branches are removed. They are quite remarkable!

"Hang on," I hear you say, "won't that cut end sprout three or four new shoots, as you have just described?"  Top marks for listening, well done. Yes, it probably will, so Donna will have to check it every couple of weeks, and gently rub off any buds that form on the cut end.

Also, if the other leader is "forced" into a fully upright position, the miracle of hormones will mean that the tree will put most of it's growing efforts into that stem, and won't send as many "grow! grow!" messages to the cut end.

But if Donna wants to keep the tree small, and to encourage it into a more Japanese frame of mind, then she can take a look at those longer, sticky-out branches, and - just as I did with the small acer in the other article - she can shorten those branches by looking underneath them, and cutting at a point where they branch. 

This is so much easier to demonstrate than to describe! I have been asked many times to put up videos of How To Do Stuff, and I'm thinking about it...

So if I had Donna's tree, and here it is again: 

..what would I do?

Assuming that it is planted there for beauty, and not for screening or privacy, I would leave the two parallel upright stems, but I would trim off the bits which are shooting off to the top left, and also to the top right.

This would give the tree more of a Japanese feel, being slightly more flat-topped, rather than having two horns sticking up.

I've put in some red lines to indicate roughly where I would chop - can  you see them?

And when I say "chop" I don't mean, chop, of course, I mean that I would carefully clip out the unwanted stems, leaving as natural a line as possible.

Or this is the drastic version, turning it back into a single-stemmed tree.

This time my red line is very low down -  ooooerrr! - and would basically remove the entire right hand side of the tree. I assume that the left-hand side is more desirable, but this is the sort of thing for which you really need to see the tree, in situ.

It might look very different from the other angle.

So there you go, Donna, does that help at all?

Thursday, 14 May 2020

Sedum: how to propagate after Chelsea Chop

A couple of days ago, I wrote about using the "chelsea chop" to prevent Sedums from flopping open, and "Stainless" reminded me that the offcuts can be used as propagation material. Free plants!

It's very simple, so well worth having a go. Here's a quick "how to do it" tutorial.

Having cut out those central stems,  right, you will end up with a hole in the middle of your clump, and a handful of shortish cut-off stems.

Take the off-cuts, gently cut off the lower leaves, and push the stems into a pot of soil or compost.

Put about five or six stems in each pot.

It is traditional to put them round the edges of the pot, but no-one seems to know why. I have done one or two experiments, not enough to be conclusive yet, but initial results suggest that it doesn't make much difference to the rooting of the cuttings, whether they are right up against the sides of the pot, or an inch in (ie not at the edge) but if you put them pretty close to the edge, it does slightly reduce each plant's roots infiltrating those of the next cutting.

Annoyingly, I have taken photos of this process twice, but still haven't managed to get a full set of photos of the whole thing... in focus! Oops, will try harder.

Anyway, having put them into a pot, leave it outside - it does not need to be put indoors, or in a greenhouse - and keep it watered.

In a few weeks, or maybe a couple of months, some, or many, or all, of the stems will have produced little tiny baby plants at the base, where they join the soil.  Allow them to grow a little bigger, then gently tip out the pot and separate them, potting each one on individually. At this point, you can cut off the original big stem, if you wish.

Let them grow on for a few weeks, until they are big enough to plant out.

Yes, it really is that simple - and now you have lots of strong young plants, ready to be planted out in your garden, or passed on to other people!

Tuesday, 12 May 2020

Chelsea Chop: it's time to hit those Sedum!

I wrote about the Chelsea Chop on Solidago (Goldenrod), but someone asked me the other day about how I prevent my Sedum (plural of Sedum, anyone? Sedums? Sedia?) from flopping open and outwards, which they all seem to do.

The answer is to apply the Chelsea Chop!

Here we are a couple of days ago, the Sedum plants (hahhahhaaa, cunning way to avoid the grammatical obstacle of the unknown plural of Sedum!) (ok smartipants, I've looked it up on the internet and it says Sedums, so I'll go with that from now on) are currently still small and compact, but we all know that won't last for long: all it takes is a splash of rain and they will be knee high or more, and will then start to flop open.

So, what do we do?

Simply take your secateurs, grab your courage with both hands, and cut out a small section in the very centre of the clump, as short as you can reach.

There you go, that's all you have to do.

Sharp-eyed reader will spot that this really is the same clump, you can see the small light green plant to the right - it's a rogue Tanacetum (Tansy) which will be weeded out eventually, but I'm quite soft-hearted about them, because they smell so great! Luckily, once you have one Tanacetum in your garden, you will have millions of them for ever more......

That's it - you have removed a small handful from the very centre, and that allows them enough room to grow without being so crowded that they flop open.

Within a few days, you won't even see the hole, the other stems will have leaned inwards to fill it.

But this summer, the clump will be much less likely to flop open. 

And as proof, if proof were required, here are a series of photos of these Sedums (see, I can do it now!) from last year:

This was taken in 2018, in mid August, and as you can see, they are flopping all over the place.

"They always do that," complained the garden owner: "is there anything you can do?"

So last year I did the chelsea chop on all of them.

One week later, you can barely see the holes - as promised!

Here we are in early August, and they are all standing up very well - such a difference from the first picture!

Note how they start off quite white, before slowly turning pink.

And finally, here we are in September, all gone pink, and virtually all standing up.

Quite a difference from the floppy ones of the year before.

So there you have it: the Chelsea Chop -  how to do, when to do it (ie when they are just starting to form nice rounded clumps), and why to do it.

Sunday, 10 May 2020

Brambles: roots and membrane

Yes, more talk about brambles!  I am seriously thinking of renaming this blog "All About Brambles" as that's what about half of "new" readers are looking for!

Anyway, another question about brambles which deserves an article to itself, as the first article - the first one of many, by the way - has such a huge list of comments and questions under it, that I bet most people lose the will to live before they reach the end.

So,  a new question, a new article.

This one comes from Vicki. (says in Michelle Pfeiffer voice:  "Ice skater, or stewardess?")  (only joking, I was watching Batman Returns last night!)

Vicki says they have just cleared an area at the back of their garden so they can extend, and that the area was previously covered in brambles.

She asks: "All the shoots are now gone, though, and the roots are still in the ground. Do you think glyphosate will still help to kill the roots? We are planning to cover the area with membrane, then bark chippings:  do you think the brambles will still grow through this? "

First question: no, glyphosate will not help at this point, because there are no new leaves for it to be sprayed onto. Glyphosate is a translocated weedkiller, you spray it on the leaves and it moves down inside the plant to the roots, then kills them. So no leaves = no point of ingress. Also, one of the main benefits of glyphosate is that it is inactivated on contact with the soil - it doesn't poison the  soil for months afterwards.  So by spraying it on bare ground, it is immediately deactivated. It won't penetrate down and kill the roots.  (cries of "Drat!" from Vicki)

Second question, will brambles grow back through membrane and bark chips.

Now, this very much depends on how the shoots were removed.  If the top inch or two of the area was removed by machinery, ie scraped off, then the growing point will have been removed and all should be well.

But if the shoots were just pulled off, or chopped off using loppers, or a strimmer, they will only have been cut at or slightly above ground level, so the crowns of the brambles are still in the ground.  In this case then yes, they will regrow, and they will either grow through the membrane, or they will push it up from underneath, resulting in strange lumpy areas.

My suggestion would be to spray the area with something like SBK, or possibly Pathclear, before you lay the membrane. If you read the instructions for both of those products, you may well be able to decide which one you think fits the bill best.

The non-chemical answer would be to leave the area as it is for a couple of weeks until the brambles start to re-grow, then you can dig them all out properly. (I can hear Vicki groaning from here.)

And the truly eco suggestion would be to get some pigs in to truffle it all up for you, but honestly, that is such a silly suggestion, and I do wish that the dippy hippy eco-warrior brigade would give it a rest: I have only known one person in my entire professional life so far who had sufficient room to put pigs on their bramble infestation: and he refused to do so because it would have taken several months, and he did not want to live with the quagmire they would leave at the end of it, and the smell, noise, disturbance and vigilance they would create and require, in the meantime. *end of annoyed rant*

Hopefully that will answer the question for Vicki!

Monday, 4 May 2020

Japanese Maple, Acer palmatum: how to improve a small tree

Time for another "How To" article!

Earlier this week I noticed that one of "my"  Acer palmatums was getting quite overgrown, and had lost its shape completely.

This is one which I rescued from a fate worse than death, ie being smothered in ivy, five years ago.

As you can see, it's still lovely, just look at those beautiful leaves, but it has turned into a bit of a "blob", instead of being shapely and stylish.

The lower fronds are sweeping the ground, which is never a good thing - they'll be chopped by the mower for a start, and they make it impossible to weed underneath it.

So, what do we do?

The first job is to crawl under it on hands and knees, grab hold of those lowest couple of branches, and follow them back to where they join the main trunk.

And then chop them off.

Then run round the other side, and see what it looks like. Oh, you can't actually see it from the other side, as the conifer blocks it completely.  Good! I need only worry about how it looks from this angle, but normally when doing something like that, you need to check round all sides after each cut, and before doing anything more.

So, that's the bulk of the big branches removed.  Stand well back, and assess it:

Ooh, that's better.

Now we can see the shape of the trunk, and we can see through it and out the other side.

And we can also see that it's quite unbalanced, there is too much on the left.

So, back to hands and knees, locate where that lowest branch joins the main stem, and cut it off.

Getting better: it's looking more like a canopy now, and less like a blob.

But now you can see that the right-hand side is too low, it's touching the low growing plants.

So, back to hands and knees, and this time I take hold of the lowest branch on the right, and follow it back, not to the main stem, but just back one "joint" in the branch system.

And chop!

That's better, now the canopy is free of the ground, and it's more balanced.

There are just one or two wispy bits on the far right which are not quite right, though, so I go in with the secateurs and very carefully nip off a couple of the lowest fronds.

At this point, it's best not to get too carried away with the fine detail, but at the same time, having taken the step to do all the drastic pruning, don't waste the effort by leaving just a few untidy bits sticking out.

Here's the final thing, and I secretly think that the left-hand branch is maybe just a wee bit too long, but I'll stop there for now, and take another look at it after a couple of weeks.

This photo might not look very different from the one above, but those couple of small extra snips make all the difference!

(I can't find a way to make an animation of them, sorry.) (well, I can, but I quickly realised that for an animation to work, you have to be standing in EXACTLY the same place for each photo, otherwise the viewer gets an unpleasant, earthquake-like experience and has to go and lie down for a while.)

So there you have it, how to re-define a lovely Japanese Maple. Be brave, be bold, and know when to stop!!

Saturday, 2 May 2020

The shortness of the gardener's arms.

That sounds like a chapter in a who-dunnit, doesn't it? The Clue of the Part-pruned Hedge...

"Hmm," said Sheerluck Soames, to Dr Wotsit, the faithful sidekick.

"The gardener who is responsible for this bed is - let me see, five foot, five and three quarter inches tall, and has an aversion to using a ladder."


Every time I go past this section of hedge, I nip off any branches which are sticking out over the grass, so that whoever mows the grass can do so with ease, and so that the grass isn't deprived of light, which would make it die: and that would be really annoying, right by the gate, which obviously concentrates all the foot traffic.

And, selfishly, so that I can open the gate properly, get a wheelbarrow through properly, and generally just move around the area without having great big wet Yew branches thwacking me in the face.

Then, when I was weeding the bed, I was again being thwacked by over-long branches, and it was getting hard to reach some of the plants, so I just nipped back a few branches each time I was working there.

I hadn't noticed how much of it I had trimmed off - and oh look! What a lovely neat corner!