Japanese maple

[Daluke]

Hey guys.

I’m in Melbourne and have a Japanese maple that I’m struggling to ramification. The trunk has great taper but really ugly branching - leggy, long internodes with huge leaves. I picked the tree up a few years back and repotted last season. Is this a residual issue - like am i feeling the aftermath of over fertilisation during the wrongs seasons from the previous owner? Any suggestions on what to do now? I feel I should be pumping it with fertilisers now and then stopping come the end of autumn and cutting back hard in the middle of winter. Any ideas?

[melbrackstone]

From what I've read you need to get the tree into smaller particles so that the roots ramify the way the branches on top are going to....they mirror each other. If you can get the mix right, and you're looking for finer growth, you also need to change your fertilising regime to medium quantities in the growing season, with not much else for the rest of the year. Heavy fertilising will only continue the coarse growth habits... Maybe one of the more seasoned growers will chime in here...

[KIRKY]

It’s my understanding to cut just as the last leaves are about to fall in Autumn. Once you have cut back make sure you are on top of spring growth they need almost daily pinching of the new growth as you may miss some the first couple of times.
What variety is it as some have smaller leaves to start with so seem to reduce quicker. Also more ramification on the tree will produce smaller leaves. Possibly? Feeding after the first flush of spring growth may help. I’m sure others will pipe in here once they get over their Christmas
Cheers
Kirky

[TimS]

Pinching the central shoot out after the first pair of leaves has emerged in spring halts the extension of the shoot into the long runners you are seeing at the moment. This is purely for refinement though. If your tree is unhealthy then it is best not to pinch back, or you want the tree or a specific branch to thicken faster then do not pinch the central shoot out and let the runner go.

If you have a large tree this will mean inspecting every shoot on the whole tree each day over the space of a week or two and even on a ramified smaller tree it will need the same amount of inspection. If you miss one then you notice it very quickly as the shoot extends to more pairs of leaves.

In subsequent flushes into summer the same applies.

[shibui]

I don't think this is residual. Many JM are strong growers and naturally produce these long internodes each spring.
Restricting fertiliser will have some impact.
Pinching new tips as mentioned by Tims seems to have little impact on my JM. Nodes are often still quite long despite constant tip removal.
I find it best to start building branching after the first strong flush. In other words, wait until December then cut off all new growth/ long internodes. Second and subsequent flush usually has shorter internodes which can be used. Reducing fert during spring will also help with less vigorous shoots.
You may find that every spring the first flush is always strong. If growth is too strong to use cut off and use the second flush growth. If the tree is strong enough to produce vigorous growth it is strong enough to cope with total shoot removal.
Over time, with many grow points the problem gradually reduces but with many JM there will still be an explosion of strong growth each spring.

[treeman]

Defoliate it and cut all the tips off now. In autumn prune back hard after most leaves have fallen and wire. Don't feed next spring and don't repot. Pinch new growth as soon as you can grab hold of the middle bud after the first 2 leaves open. When the new leaves have hardened, defoliate and repeat......

[MJL]

On the way to the test at the ‘G - I may as well browse the forum to pass time on train.....

My JM forest trees are quite young. Someone told me - in the past - that I should not totally defoliate a young tree. Whether correct or not - I listened.

So.... I have partially defoliated my maples 3 times since the first spring flush. Essentially attacking those shoots with long internodes once the leaves have hardened off.

The effect of this is smaller leaves on second flush. Internodes are generally shorter on growth that springs from defoliated branches.
It also causes significant new bud growth in new and old wood.

This approach has the added benefit of me being able to hope for and encourage growth in areas where trees or forest needs to fill gaps.

As each season passes - I get more aggressive with the amount of defoliation at any given time.

I feed all through Spring and Summer and ease off in autumn and winter.

Normal caveats apply - you are better listen to experienced folk like Treeman, Shibui and TimS ... I am not expert - just learning as I go and sharing my approach.



Bonsai teaches me patience.