Garden School:


Garden School:
Teaching this week: nothing other than self-reliance, as I'm on holiday all week, yay!

Monday, 28 July 2014

Salix caprea 'Kilmarnock' - Guerilla Gardening

I wrote about this poor little tree back in February.

It's a Salix caprea 'Kilmarnock', a very common popular small ornamental tree, the top section has weeping foliage, grafted onto a normal willow rootstock.

The problem with grafted trees is that you have to keep removing any growth from below the graft, as it will be from the "ordinary" rootstock, and it will quickly overwhelm the more decorative top.

This also happens to curly hazel (one of my least favourite ornamental trees - looks fine in winter, very structural, but in summer it just looks diseased!) which tends to be ruined by long straight growths coming from the base.

This particular little tree is in the grounds of a local Tech Park, and I happen to know the groundsman quite well, so I obtained his permission to tidy it up.

The first job was to remove all the long straight stuff growing up from the base.

This is best done by pulling off the new growth, which discourages re-growth. However, in this case it had been allowed to run wild for a year, so the new shoots were too thick to just pull out - I had to cut them.

If you have to cut them, cut as close as you can to the trunk, and try to do clean cuts, no ragged bits. Sharp tools are a great help.

Then I removed an outcrop of straight growths which were sprouting part-way up the main trunk.

Finally I looked at the mop-head of pendant foliage, and applied the famous "Three Ds" of pruning - you remove anything which is Dead, Diseased, or Damaged.

Why do we do that?  Dead:There is no point leaving dead wood on a tree - it rots, it attracts wood-boring insects, it harbours other pests, it prevents air circulation, which is important for healthy new growth, and finally it looks terrible!

Diseased: any branches with fungus, or rot, or wilt, or anything unhealthy-looking will only spread. Remove any such material, cutting back progressively until you get to healthy wood.

Damaged: branches that have been broken, or snapped, are open doorways for disease to get in. It is better to cut them out straight away.

Despite this, I removed any branches that were rubbing against other branches: with regret, I also removed a couple of branches which were making it look very lop-sided. It's often hard to do this, particularly when there is so little to work with, but trust me, I'm a professional!

Finally, a little light trimming of any disproportionately long twigs, and I was done.

With all that removed, there didn't seem to be much left. As you can see (left).

Brutal, huh? But this is the correct thing to do.

Here is my reward: two months later, in May, the top was shooting nicely, and it was starting to look more as it should - a "light, airy waterfall" is what we are aiming for.

I had asked my friendly groundsman if he would re-stake the tree, to get it more upright, but unfortunately he didn't get around to doing it.

But never mind, at least it is no longer reverting back to a mere bush of grey willow!
And here it is today, July: as you can see, it's recovered beautifully, and the new growth is almost down to the ground!

Sooo worth doing....

I will be keeping an eye on it from now on, now that I have permission to do so, and hopefully it will never again get into such a mess!

11 comments:

  1. Not quite guerilla gardening then if you had permission from the groundsman? I had happy visions of you creeping out in the wee small hours, secateurs in hand. I have young weeper and will be following your advice for shaping.

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  2. Hahaha, you are right, Louise, it's not "quite" guerilla gardening! Although I rather like the idea of sneaking out at midnight, secateurs in hand, to improve small shrubs - sort of anti-vandalism?

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  3. Very cool Rachel. Brought one for my Japanese Garden but am worried especially as I planted it about 30cm away from a wall. Will this be okay or will I have to print do it doesn't get too big? It is roughly about 75cm tall..

    Thanks!

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  4. Hi Jasdip, the simple answer is that if you bought one that looks exactly like the one in the article, ie a short upright trunk with a mop of weeping branches all at the top, then it won't get any taller. It will thicken up in the trunk, and the weeping branches will grow until they lie on the ground (if you don't maintain it properly!) but it won't get any higher, and shouldn't affect the wall.

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  5. Hi Rachel! It appears my salix kilm. Has not survived a drought last August and i assumed i had to throw it out but it appears the rootstock trunk has lived. It is indeed throwing out some leaf shoots. Normally i would pinch these off, but where i cannot find any life in the top i am considerig removing the graft to grow the ordinary bit. Currently in a pot. Thoughts??

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    Replies
    1. Hi Kate! The problem with allowing the rootstock to re-grow is that it will turn into - well, a full-sized willow tree. The rootstock is normally something like S. caprea, goat willow, which makes a tree, ooh, let's see, 30' high or more?

      Honestly, I wouldn't bother! There are plenty of goat willow growing around rivers, streams, ditches, canals (disused and active) all over the country, you really don't need to nurture one in a pot.

      I'd turn it out of the pot, discard the willow, and buy something new and lovely to go in the pot!

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  6. Great advice, Rachel. we certainly don't have space for a proper 30' willow nor do I expect his to be bonsai practice to train it in a pot! Kind regards

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  7. Hi Rachel, I have a question about the roots of the Salix Caprea Kilmarnock willow.
    I have 2 in large pots, been in these pots for 5 years, I’ll hold my hands up to ‘letting the garden grow itself’ and have neglected them. This year they don’t look happy. I’ve watered and fed them through this summers heat and now it’s raining we have some green back but there’s a lot of dead wood unfortunately.
    I’d like to put them in the ground but am worried about the roots and how wide they will likely travel. The trees themselves are probably only around 5 feet tall.
    Thanks for any info you can offer, I really don’t want to lose them.

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    Replies
    1. Hi Tracey, that's a question in two parts: the first part is the dead wood, which you will have to remove. It doesn't do any good, and as it dies it actively invites pests and disease, so it's best to snip it out, carefully.

      Don't beat yourself up over this - it's been an astoundingly hot summer, and I can tell you that, as a professional gardener, I have spent more hours with a hose (in other people's gardens) than I have ever done before. I've even been watering in gardens which have never, ever needed watering before. Plants in pots are peculiarly vunerable to lack of water, so it's no disgrace that your pots have suffered a bit.

      The second part is the option to plant them out: as they are grafted plants, they won't ever grow any taller, whether they are planted out or in pots: in fact, if you plant them out they will suddenly look even smaller, as they'll be at ground level! So you won't get the same huge and invasive root spread that you get from a "natural" willow tree.

      But, having said that, the roots are still those of a proper tree, so if you ever lose the top part of the tree and don't notice that the rootstock is shooting, then you could end up with a full sized tree, and therefore full sized roots. Generally speaking, the roots will grow as needed to balance the tree: as long as it remains a grafted dwarf thing, the roots won't spread far and wide, but as soon as it is allowed to revert, they'll be off like rockets!

      So it's your decision: as long as you keep them properly maintained (which is easier in a pot as a) they are usually near to the house and b) they won't get swamped by other growth, to distract your attention from their low-level suckering habits) there shouldn't be any problem with planting them, but if you are worried, then de-pot them, root prune, and re-pot into fresh compost. This, combined with removal of dead wood, and the watering and feeding you have been giving them, should get them back into good shape.

      Hope this helps!

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  8. I have one of these and my partner has just cut it off near the ground. Is it easy to get the roots out completely?

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    1. Hi Maggie,

      Yes, it's quite easy as they are comparatively small trees. Loosen the soil all around what's left of it, and use the stump to rock it to and fro.

      This shows you where the "big" roots are, the ones holding it in place. Trace them as far sideways as you can, and cut them off. You should then be able to lift out the stump and the roots, leaving a fair-sized hole. Fill the hole in with earth from elsewhere in the garden, then either lay turf or seed over the bare patch... or plant something else!

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