Bonsaify | When to Pinch Japanese Maples and When to Let 'em Run! 

Yes, if the plant is healthy (and you don't need to grow branching or increase trunk girth) then pinching can be done to slow the spring growth and reduce internode length.

JM should backbud copiously when they are healthy and you do cutback. Mine even backbud on the trunk where I don't want buds, so I rub them off.

It's a good point. I think that in the general nursery industry they avoid seedlings from cultivars because a good portion are genetically weak. I've been starting seed collected from Arakawa (rough bark) and a few other cultivars and there are always a few that just grow so slowly or die after a while for no good reason. To be fair, most are fine and interesting to grow. As for this one - I think the problem is largely that summer in SF is just too cold for maples. The growth on it has been quite vigorous in some years while others there is dieback. That makes me think that it's the weather or watering habits etc. Last summer it was okay, but I think it got some mildew which weakened the growth further.

I would leave the sacrifice branches to run - removing any foliage that will shade branching you want to keep. For the fine branching - generally pinching, alternating with wiring and short runs of growth can give good results. You need to both build the structure of the branching and maintain it as small and delicate as possible. The first section might be a bit larger, but all the secondary and tertiary branching should be as small as possible.

@@Bonsaify thanks for the interesting input....what about timing? Do I need to prune more then 2 times a year?

Timing of pruning is based on the growth of the shoots, not on the time of year. In spring, pinching has to be done multiple times to catch the tips at the right stage of growth. Later in spring and into summer the size of the new growth is what determines the timing.

This tree is very similar to bald cypress which I own. Your explanation is wonderful. Thank you.

If the tree is healthy, yes. But whenever health is in question the best thing is to allow some growth to happen freely. A few nodes on a branch wont make it too coarse. In this case it was repotted a month or so ago, and the growth looks good so I have no qualms.

There are two sides of bonsai - artistry and horticulture. You need to know your horticulture to know how far you can push a tree. There are signs that maples show when they are weak versus when they are healthy. Allowing things to run increases vigor - but with AP you need to walk the line between vigor and ill health to maintain short nodes and small leaves. If the vigor starts to decline you can add more fertilizer, pot into a larger container or allow shoots to run. If the tree gains too much vigor you'll just have coarse branching. Good luck with your growing.👍

​@@Bonsaify"AP"? I don't know what that means, as a novice

in this context - Acer palmatum - the latin name for Japanese Maples. APL is "Akadama-Pumice-Lava' - a soil mixture. So in another context AP could mean "Akadama-Pumice" but I normally don't use that as shorthand.

I'm not familiar with Chinese maples - but generally I apply these techniques to all maples. I also work with European field maple (A. campestre) and red maple (A. rubrum)

Pomegranate leaves are not as big normally, but yes. These same principles apply to many if not all deciduous trees. Zelkova can be pinched, or let run and cutback. External defoliation, or other partial defoliating techniques can be used to balance vigor of individual branches. It's not universal but it does apply to many trees.

No, I don't think so. Hornbeams can be partially defoliated, but you'd want to wait until they grow out a bit. I would recommend you read some of Jonas' blog posts on the species: bonsaitonight.com/?s=Hornbeam

I do not recall senator. 🙃 One of the problems with propagating thousands of plants is that each little one starts to get a bit fuzzy in my brain. And now that you mention it - I'm not sure this actually was an air layer. But I did do the video on three air layers from one of my trees. And there was a second tree that you did air-layers on, which I removed after you left. I think this is one of those.

Ah yes I forgot the air layers.

Actually I mis-spoke on a couple occasions - nodes are the junction, internodes are the space between the junction. Buds come from nodes, and you are reducing the internode length to make it easier to get tight branching.

as often as it needs it.😜. TBH, totally depends on the growth of the tree. With maples in refinement you don't want to allow long coarse branches - so pinching and thinning are important.

@@Bonsaify Thanks for taking the time to answer. I love your Shohin and Mame trees, so your answer is precious to me. Thanks for teaching