Garden School:

Garden School:
Teaching this week: Rose pruning (as always!) and water management

Friday, 29 January 2016

Elm tree suckers: how and why to remove them.

I wrote a while ago about removing dead Elms: one of the associated problems with Elm trees is the many suckers that they throw up for yards around, and today I was asked to remove a couple of these suckers, from the original dead tree, that were making their way out of the hedgerow (where we don't mind them growing) and into the main meadow (where we are not so keen on them).

In case you don't already know, most of the Elm growing in the UK is Ulmus procera, better known as English Elm or Common Elm and yes, it's the one that gets Dutch Elm Disease. This means that we no longer have huge mature trees of this species: instead we have hedgerows full of healthy young trees, but as soon as they reach a certain point, they die.

Opinion is split as to how, exactly, they die: some books say that the trees can resist the infection for about 15-20 years: others say that the infection enters the trees via small beetles carrying the sticky spores on their backs, and that these beetles are attracted to the flowers, so until a tree reaches sufficient maturity to flower, it won't be susceptible, but as soon as it does, the insects which bear the disease find it, infect it, then it is only a matter of time before they die. Either way, you will hardly ever find an Elm tree that is more that about 20' tall.

The good news is that Elms send up suckers with great vigour, so even if the bigger trees die, there will still be others to replace them. Which is fine in hedgerows, less good in gardens, and no use at all if you wanted to have a specimen tree. However, in our meadow, we are happy to have a thicket of Elm suckers around the edge - but when they start trespassing into the meadow, my Client looks at them with furrowed brow, and instructs me to get out there and get rid of them.

On this occasion there were a handful of slender young saplings to be removed, each of them taller than me, (memo to self: must encourage the Client to go out into the meadow more often so she spots them before they get this big) and about thick enough that I couldn't get my finger and thumb all the way round the stem at the base.

Now, the cunning part about removing tree suckers is that you don't have to dig a whopping great hole: they spread by horizontal roots, which run just under the roots of the grass, and send up new growth wherever the fancy takes them: you tend to get them in straight lines. They might look like random growth at first, but in this case what appeared to be half a dozen saplings turned out to be just two roots, one with four new trees on it, one with two.

All you have to do is work out which way the root is running, get a fork or spade underneath it and lever it up.

Here's one I did earlier - as you can see, there is the one good strong sapling, and a couple of inches further along the root, a second one, much spindlier.

You can also see that the root is continuing to head off into the meadow.

Note also the almost total lack of "roots" in the sense of a mat of small feeder roots: these saplings are taking all their nourishment from the original rootstock, and if severed, would just die.

So why don't I just cut the big root? Read on.....

Knowing which way the root was running, I was able to heave up the root for several yards back towards the hedgerow, using a combination of slitting the turf along its line, and levering up with the spade.

By the time I was "off" the meadow proper, the root had become about twice as thick as it is in this photo, and was putting up a lot of resistance, so I simply cut it off as short as I could, and trod down the slit in the grass.

There is every chance that it will throw up a new sucker from the freshly cut end, of course: but that's ok because it is now back into the line of the hedge, and furthermore, small suckers can easily be mown off, or better still, ripped off from the root, if they are spotted in time.

As a piece of general advice for removing suckers, if you "cut" they will tend to re-sprout, but if you "tear" or "rip", then they will generally lose interest. This is of more importance with grafted trees and roses, of course, but I mention it in case you catch your Elm suckers at a much earlier stage. If they are only tiny tiddlers, a few inches high, then it is better to scoop aside the soil so that you can see the root, then take firm hold of the sucker as close to the root as possible, and rip it off.

And that, dear readers, is the reason I didn't simply chop off the root where it was - if I had done so, it would probably have simply sent up a whole bunch of new suckers right at the cut end: right where I don't want them!

Tuesday, 26 January 2016

Salix caprea "Kilmarnock": why can't it be grown from seed?

I have written a couple of articles, now,  about the Salix caprea "Kilmarnock": I'm not, generally speaking, a big fan of grafted trees, but this tree is a great way to get something small and wildlife-friendly for a small garden, and they are really quite easy to manage, once you get the hang of it.

I wrote about a particular little example of this tree which had been totally neglected, then brutally pruned by me, and which had subsequently been restored to full health and beauty, which was quite a result *punches air*.

 Here it is about this time last year, with silky catkins, nicely demonstrating the "light airy waterfall" effect.

The original post continues to get a lot of views, and the other day there was a question from Steve ("Hi, Steve!" *waves*) asking about why we can't grow them from seed.

There are three answers to this (very interesting!) question: the first is that the small weeping Kilmarnock is a grafted tree: it's about as un-natural a tree as you can get, because the top or "weeping" part is grafted onto a straight upright stem of a different type of willow. This, incidentally, is why these trees don't grow any "bigger" over time - they just grow wider (and more dense, if they are not pruned properly), which is why they are ideal for small gardens.

But a grafted tree is two different trees, artificially joined together to get the desired effect, which means that if you take seed from the top, the part above the graft,  any seedlings won't look at all like the parent. And yes, if the bottom part of the tree is allowed to grow and flower (which is a bad idea for many reasons) any seedlings from that won't look anything at all like the parent either.

The second point is that all willows are industrially promiscuous, the little beasties, and they will pretty much all pollinate each other. This means that you will have no idea whatsoever as to which willow pollinated your Kilmarnock - it could have been from the nearest other willow, it could have been from one half a mile away - so the seedlings could be any sort of hybrid willow, but will most definitely not be a standard-with-weeping-top.

The third part of the answer lies in the fact that they are, as Steve says, dioecious. A dioecious tree is one where each individual tree will produce either male flowers, or female flowers, not both.

The clue, for all you budding botanists out there, is in the name - dioecious means literally "two houses" and dioecious trees have two types of tree, one of which produces only male flowers, one of which produces only female flowers. You will usually be completely unable to tell whether a given dioecious tree is a male or female - or, more properly, a male-flower-producing or female-flower-producing - until it actually flowers.

The opposite is monoecious ("di" always means two, "mono" always means one)  which means, as the name suggests, one house, ie one individual tree will have both male and female flowers on it. The advantage is that they can, if desperate, self-pollinate. The disadvantage is that self-pollination uses all the same genetic material, so there is less chance of mutations. This might not sound like a disadvantage: surely you want all your little willow trees to look just like the big willow trees? But on an evolutionary timescale, changes are essential to allow the organism to cope with changes to the environment.

Holly, like willow, are dioecious, and you may already have noticed that not all holly trees produce berries: only the female ones will do so. 

Birch and Alder, for your information, are examples of monoecious trees which produce both male and female flowers on the same tree.

Willow are dioecious, which means that even if your particular Salix caprea Kilmarnock is female and therefore produces seed, it will by definition have been fertilised by a different Salix - leading to the problem mentioned at Point Two, ie hybridisation: the seeds will not be the same as the original, as the pollen will have come from a different, male, tree, which might be a different species of Salix altogether.

Both male and female willows will produce the silky catkins but they are subtly different - the male flowers mature into yellow-ness, as the pollen becomes apparent, and the female ones mature from silky silver-grey into green.

So there you go, Steve, now you know everything there is to know about grafted trees, promiscuous willows, and catkins! (well, not quite everything.....)

Sunday, 24 January 2016

Common newts in my pots again!


Here we are, middle of winter, not the traditional time for gardening but it's a nice mild day, so I decided to check over some of my "stock" plants, which will be ready for sale later in the year.

I tipped this one to see how the roots were coming along, and the answer is "quite nicely" but we appear to have a little friend in there as well.

Can you see him?

He's upside down, and slightly out of focus, but that orange thing is the underside of a common newt, head towards the top, tail hanging out over the side, and one poor little limb flung outwards in a despairing "WHY will she not let me SLEEP!" sort of gesture.

I am constantly amazed at the number of newts that I find in my garden, because when I say "garden" I mean my small front yard, which has no pond, no grass, no flower beds, no shrubs, nothing, you would have thought, to attract newts.  It is entirely shingle underfoot, and almost entirely covered with raised benches for my plants-for-sale.

In fact, here's a picture of it:

What look like long flower beds are the raised benches - spot the blue mushroom trays!

So why are my pots always full of newts?

I assume that they like the matrix of cover created by the pots - all the tops meet, so the predators can't get at them, but all the bottoms are narrower, so there must be a network of alleyways between the pots.

And, of course, I water them frequently so although there is no pond or soil, there is quite a lot of shade and dampness.

And whenever I find one, like this little fellow, I carefully put them back somewhere: so presumably the word has gone out, in newt circles, that my front yard is a superb winter hiding place with a kindly if somewhat annoying owner who will keep on moving things...

Thursday, 14 January 2016

Water Butt FAIL!!

 I was talking about a water butt fail the other day - which reminded me of this little fiasco from a couple of months back.

I have a (new) Client whose house completely lacks water butts... there are a couple of them floating around loose behind the shed, and diverters on the down pipes, but nothing is connected. Shocking! Don't they know that rainwater is free?? And nicer for the plants than nasty chlorinated old tap water? (which is still better than letting them die of drought, of course.)

So I asked if their handyman could re-install them.

Normally I would just do the job myself, but in this case I have quite enough on my plate to get the (large) garden under control with just one morning a week in which to do it... so I thought I'd ask the owners if their handyman - who did a very average job on painting some metal gates - would kindly re-fit them.

Oh dear.

This is what I found:

Right, where shall we start?

Let's start with what it's standing on. Instead of the usual green plastic base (which I left handily next to it, ready for use) he used a concrete slab - less than elegant, but I could let that pass if the butt were sitting centrally on the slab.

As you can see, it is not.

Secondly, can you see that wooden construction just immediately behind the butt? That's the pump cupboard, it needs to be accessed a couple of times a year, or more if there is a problem. The front panel is screwed on - it would be interesting to watch the pump engineer trying to squeeze his way in....

Thirdly, there is the matter of the wet patch underneath it.  Is it leaking? Is that why it was disconnected in the first place?

Closer inspection reveals this unbelieveable bodge job:

Fourth item on the "Fail" list: the joint onto the white pipe is not tight at all, it's a push fit, and it's dripping.  All over the corner of the plywood pump cover.

Now, call me old fashioned, but I don't like to have water dripping onto plywood - it tends to delaminate and then fall apart. This would mean having to have a new cover built, which is an unnecessary expense, not to mention the general annoyance of having a permanent damp patch, moss growth, slipperyness of surrounding patio slabs, unsightliness of the damp patch, risk of dampness damaging the underlying patio, risk of constant dampness damaging the foundations, etc etc. You get the picture.

This led to Fail Number Five: the water was sheeting out of the lid of the butt, because - as any idiot can see in the above photo - the inlet pipe is way, way higher than the top of the butt.

As you can see - right - the water butt is filled right up to the very lid!

Now, in case you are not totally familiar with the workings of rainwater diverters in down-pipes, this is the principle:

Water runs down the inside of the down-pipe, into a box (the diverter) which fills up, then the water tips over inot the inlet pipe. This pipe runs into the water butt and fills it. When the water butt is full,  and the water reaches the level of the inlet pipe, it runs back up the pipe, back into the diverter box, and overflows back down the down-pipe. This is a little similar to the principle of a ball-cock in your cistern - for as long as the cistern is not full, the valve is open and more water trickles in. When the cistern is full, the valve shuts off and no more water enters.

Water butts diverters don't have valves - instead, they have to be installed at exactly the right height so that gravity can do all the work. As you can see from the water sheeting out of the top of this butt, the handyman has installed the butt way too low.

As it we didn't already know that it was way too low.... can you spot the mistake in this photo.

Yes, Fail Number Six, the tap is so low that you can't get the watering can underneath it.

And you can also see how far off-centre the whole wretched thing is, as well!

This sort of thing really makes me spit - how can any workman do such a  bad job, and still sleep at night? And how can any so-called "handyman" be unaware of the basics of water butt installation? I would have thought that any handyman would have seen a dozen water butts in his first year, and this chap is an old boy, so I really think he should know better.

So what did I do? What could I do -  I immediately de-installed the water butt: I pulled off the connector,  removed the inlet pipe altogether, and blocked the hole in the diverter. Any small amount of water that drips out of the blocked hole will run harmlessly down the outside of the down-pipe and into the drain.

This meant it was "safe" while I gradually emptied the water butt so that it could then be properly re-installed, under my eagle eye. And next time, I will darn well do it myself!

Tuesday, 12 January 2016

Yucca and how to tame them

Winter is a time for busy bloggers to catch up with posts from earlier in the season - well, that's my excuse for this post being "out of time", anyway! This is a job that can just as easily be done now, in mid-winter, as it can in summer - it's one of those jobs that you do "when there is time to get around to it".

Back in the early summer, I had grown extremely tired of being stabbed while weeding around a particular Yucca, which was badly infested with bindweed, meaning that I was forever trying to dig out the bindweed roots, but failing to get all of them because I was being stabbed to depth by this blasted plant.

Finally, I finally lost patience with it.

All you have to do to tame an overgrown Yucca is to crawl underneath the canopy of leaves with a pair of loppers - be careful as you do, as each leaf has a terminal spine which is rock hard and quite capable of piercing skin. How do I know? One stabbed at my forehead as I approached this plant, and it wasn't until the blood trickled down my forehead that I realised it had broken the skin!

Anyway, work your way carefully underneath the plant, then simply lop off some of the outer growths. The stems are actually quite soft, and you won't need a pruning saw.

This much came off:

Yes, pretty much a whole wheelbarrow's worth, which went straight onto the bonfire heap. There may be some greenery there, but the tips are resinous and very sharp, and the structure of the leaves makes me think that they would take a long, long time to rot down.

Furthermore, I am paid to do the garden, not to pick fussily through the cuttings, so whee! on the bonfire heap they all went.

And this is what was left:

Much better!

You can see in the photo to the right, the white circles are where I have removed entire limbs.
This particular one had had its top broken off last year, when the people next door felled a large tree rather inexpertly, dropping several branches over the fence into my Client's garden. So it had lost the rather nice upright shape of a proper Yucca, and instead was a rather untidy clump at exactly stab-the-gardener height.

Instead, I am going for the Yucca Copse effect, to see what it looks like - and if neither I nor the Client like it, then I will go round with a fork and dig up all those outlying baby Yucca plants, allowing just one central stem to re-grow to a decent height.

Or at least, that's the plan!

Friday, 8 January 2016

The Leaning Water Butt of Pisa

Well, maybe not of Pisa...

.. but it's certainly leaning!

This is what happens when your Client's lazy workmen lay lovely decorative brick pavers (like bricks but without the indented "frog" on the underside) to make a neat apron in front of the toolhouse door.. but fail to make a proper concreted edge for it.

They then plonked the water butt right on the very edge of the loose-laid brick pavers.

And is anyone surprised at the result? The weight of the water - which is conveniently 1kg per 1 litre, and it's a slimline 100 litre water butt, so you can do the maths yourself - pressed down on the pavers, there is no edge to stop them spreading, and whoopsadaisy, the whole thing starts to lean.

Worse, once a water butt starts to lean, it often over-fills, and the water then dribbles out of the lid (along with all the rainfall on top of it) and runs off the downhill side, so the earth under the spreading pavers gets extra erosion, offering less and less support to the pavers.

We all know where this is going to end, don't we!

If you are faced with one of these, the proper solution is to unplug the filler pipe so no more water goes in: use up the water in the butt, then lift it off the plastic stand. Move the stand out of the way, relay the pavers onto a concrete mix instead of onto sand, and if at all possible, concrete in a line of edging stones, to support them.

If you can't do all this, then the cheapo answer is to empty the butt as above, and find a single concrete slab that is big enough for the plastic stand. Put this under the stand, chock it up as necessary to get it level, then replace the butt, and reconnect the filler pipe. Be warned, however, that by doing this, you raise the butt by the thickness of the slab, so it might not fill properly.

This leaves you with the options of either having to excavate under the loose laid pavers (thus worsening their problem) to lower them by the thickness of the slab - or having to drill a new filler hole in the side of the butt. Both of these options are tiresome.

If you are lucky, you may find that the sinking of the pavers is more or less the same as the thickness of the slab, in which case everything will work perfectly: or, you might be able to adjust the section of the downpipe where the filler pipe originates: often they are quite loosely fitted, and you may be able to wedge the downpipe end of the pipe at the top of its range, so to speak, so that the water will flow again.

Honestly, where in the job description for "Gardener" did it say "Water Engineer"?!