Help Long internodes Maple forest

[Akhi]

Hi Guys,
After a couple of years in a plastic pot, I decided to repot my 4 year old maple forest into a terracotta pot. While the forest was less aggressive in its plastic tray, following repotting has gone berserk and is throwing out lovely growth but coarse with too long internodes.
Do you know what I might have done wrong? I had pruned the roots by about 1/3rd when repotting.
The soil I had used was a mixture of perlite, composted pine bark, perlite and cow manure topped with a thin layer of fine soil to hold the moss.
Any suggestions, experience is appreciated. The crazy growth has spoiled the whole look of the forest with such large leaves.

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[Firecat]

hi Akhi.
My easy fix..defoliate now.
Others might say wait a little but the Maple is bounding away and they will lengthen while you are watching them..
Even as a start knock out all the big leaves first.
I'm happy with my suggestion and will be in agreement with any other ideas to get this tree in good order....There are some 'gun' growers here.
Steve.

[Akhi]

Thanks Steve will get to this over the weekend. So do you think I should cut back this year's growth as well?

[Pearcy001]

The cow manure would be helping to feed the plant, adding to the heavy growth. Is this the first time you've added it to the mix? If it is just a layer on top and you want to reduce the growth rate you could scrape it off. If you are also fertilising heavile on top with liquid feed you could slow it down too, but remember the tree's health should come first so do not stop fertilising completely. I believe some people advise not to fertilise until after the fresh growth has hardened off.

Just to clarify, is it the leaf size or internode length that is bothering you?

Also what is your fertilising rageme like?

Cheers,
Pearcy.

Sent from my SM-G920I using Tapatalk

[Akhi]

Hi Pearcy,
I had mixed the cow manure in the soil mix so can't separate it. The inter nodal gap is my concern not perturbed about leaf size as I think that will reduce as the trees age

[Pup]

Standard pruning of maples to get short internodal growth is to pinch out the new growth tips. It promotes ramifications and shorter internodes

Cheers Pup

[Andrew Legg]

I second Pup. Pinch out the new growth before the internodes get to long. Do the same for the next growth spurt. Then let the new growth that result grow out further to thicken up a bit and harden off. You can then cut back hard to the second bud set with the short internodes.

[shibui]

What did you expect after root pruning, giving the maples extra root room and feeding it? Each of these things will result in extra growth. All together it adds up to even more growth.
I don't think this extra growyth is a bad thing. The extra growth will add some thickness to the trees. You control how much by the way you pinch the new growth. Any coarse growth with long internodes that is out of place can be cut off - either straight away or later in the season depending whether you want more or less thickening.
Note - you will want the centre trees to thicken more than the outer ones so manage each one individually. Often the outer ones which have more access to more root room will grow faster than the centre ones so keep an eye on them.

[Akhi]

Thanks guys, so is it safe for me to go and clip most of the growth off? All growth had the first pair of leaves too far from last year's node. There are not many that were close together.
Shibui note your point on a middle tree. I am developing that outside this as I lost one so left with only four in that group. Planning to bring that into the planting in a couple of years

[Matt S]

Hi Akhi,

As Shibui stated don't worry about the long internodes on the trees you want to thicken, you'll only slow down the process if you start pruning/pinching.

Once you're at a stage where you want ramification you'll need to pinch out the new shoots as soon as they appear, for both the first flush of growth in spring and any subsequent growth as a result of pruning. As soon as the first pair of leaves appears, get a pair of tweezers, separate the leaves if necessary and remove the shoot coming out in between:

Acer pinching out.jpg

This will stop long internodes from forming.

Matt.

[Akhi]

Thanks for the picture Matt. Crystal clear now. I waited till it had three pairs of leaves. Thank you all for your help and will post an update once I get to it this weekend

[shibui]

I believe that Matt's picture shows technique for more advanced maples where development is close to complete and the aim is to limit further growth. For developing maples it is OK to allow longer shoots to develop then cut back. The extra growth will promote trunk thickening, etc. Allow shoots to grow 3-6 pairs of leaves then prune back - if first internode is ok leave 1 or 2 pairs of leaves, if first internode is long, cut below the first leaves and new shoots will sprout from the base again. Usually the second round of growth is a little shorter. Watch out for multiple shoots forming. Sometimes 3 or more shoots will grow from the original base. If you leave them all it will thicken at that point very quickly so always reduce new shoots to only 2 at any point.

There is no problem cutting new shoots close to the base if you need to. New buds will form.

[Akhi]

Well in that case I will selectively prune now for a more harder prune in winter and pinch next spring

[Akhi]

I couldn't bring myself to chopping all the new growth that the plant had put though particularly since I had just repotted it this winter so ended up partially defoliating the aggressive growth while retaining a small piece of leaf on each petiole. Now fingers crossed for the new growth and hopefully I will have a lot of backbudding.

Maple forest partial defoliation 1.jpg

Maple forest partial defoliation 2.jpg

[treeman]

Defoliation will help but not on it's own. First defoliate the tree. When the leaves have fully matured is the correct time not now. (do it to the whole tree except for the very weak areas) When you do this you will notice that in some areas, you will be still left with long internodes. For a tree the size of yours, anything longer than 25mm is too long. If you let the new leaves form there, you won't solve that problem. What you will need to do is to cut off the entire internode to a section with shorter tighter growth. Even if there are no visible buds to be seen, they will form. Select 2 from these and let them put out 2 leaves and a central bud. Then pinch out the middle bud as soon as you can grab it easily (although not too early as this will weaken the shoot too much. When the leaves are half developed is about right). The trick with these is to be consistent. You need to look over the tree every day in spring and pinch out the centre buds when they need to be pinched out. Leaving for just one more day can be too late. Don't over water the tree. J. maples do not need much water. Don't feed the tree too much. If it has been repotted that year, do not give any fertilizer until summer.