Species Selection - Leaf Reduction

Howdy howdy,

So, this question has been bouncing around my noggin: If I can find mature, hardened off leaves that are quite small on a tree that typically has larger leaves (like acer macrophyllum/big leaf maple), would it stand to reason that that species has the potential to reduce the leaf size down to at least that level? I’m just looking out my window as I work into the mid-canopy of a big big leaf maple and seeing itty bitty leaves in some places. I’ve noticed this in quite a few other species and I’m wondering if the concept is sound. The concept, in a sentence: “It’s capable of producing tiny leaves, so it might be able to be reduced to that size with enough ramification and work”

Often, it’s just a matter of finding the correct technique… or hitting the jackpot on the genetic lottery and finding a seedling that reduces the leaves on its own. The correct method may be defoliation, densification, keeping it rootbound… or a combination of several things.

An extreme example that is not mine, from a friend… the large one is a horse chestnut leaf, the small one bottom right is also a horse chestnut leaf after 2 years of leaf reduction work. The tiny one is still a horse chestnut leaf after 11 years of training for leaf reduction. The madman now has several mame horse chestnuts on his shelves. It’s a species that is on the “leaves are too big to make a bonsai” list.

The technique is simple-ish enough after you’ve developed the trunk you want:
-defoliate when the leaves are fully deployed
-remove all terminal buds at the end of winter
-select the latent buds that wake up

I’ll try it myself this year.


It seems to me, in mature deciduous trees that the density of ramification is the control for leaf size, so apical growth has much smaller leaves than lower growth. So too in bonsai I suppose.

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Holy butts. I was just walking under a horse chestnut yesterday and thinking “man, such a beautiful tree, too bad the leaves are so big!” The one near my house has a hollow where a branch was that collects water and creates a little pool (inevitably filled with all sorts of invertebrates) and I love it’s big knobbly nature.

I’m actually seeing this right above the bottom branch rather than the tips of the canopy, though I do see some little ones near the edges!

Interesting, could just be very weak growth. Shows what I know!

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Yeah, it’s weird, I see them just here and there throughout, from really close to the big trunk, halfway out on a branch, and a few right near the tips. They’ll be right next to dinnerplate sized leaves too. My theory is that the tree put a TON of energy into making this monster leaves with its first push, and then right after that is like ‘oof, I just spent all of my resources and really would like to produce more growth, but I’m pretty tapped out for the moment’. Or maybe they came out at the same time where it had lots of energy to devote to the main happy buds, but then didn’t quite invest the same in some others for some reason. They’re surely nowhere near how small japanese maple leaves can be, but they’re still small and might look kind of nice on a larger bonsai. Lemme see if I can get a picture for ya

Interesting. This could well be an early secondary flush due to its vigour, that smaller leaf is less pigmented and the petiole doesn’t look hardened off yet. If so could well double in size over the next week or two if conditions allow.

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@zlessley I agree with @Silva_Naturalis, it’s just a younger leaf I think you’ll find. Good chance it would have grown larger with eventual size being closer to the first flush.

You control the leaf size when the tree is in a containerized environment. As Ryan has said before on the “gas and brake pedals”