Defoliation of newly repotted trees

redfokker

Defoliation to produce smaller leaves is the question....Since I am new to the hobby, all my trees are in their first season of being potted. Should new
trees be left alone due to the stress of being repotted? I have two spiecies that I am wondering about. First I aquired a Katura tree (Cercidiphllum Japonicum). This tree started putting on beautiful leaves early in March, they start out red and turn green as they develop. The internodes are kind of long (I think). Pruning will be my next learning curve.

Secondly I have a "little leaf Linden" (Tilia Cordata). Little leaf seems to be a relative term.... Both are doing quite well and leafing out prolifically.

Should I resist the newbie tendency to mess with them this season?

Attached Images

	potted linden 400x.jpg (55.7 KB, 29 views)
	leaves linden 400x.jpg (39.3 KB, 15 views)
	april katsura 400x.leaves.jpg (34.5 KB, 20 views)

__________________
REDFOKKER
Albany, Oregon Zone 7

Advertisement

David Yedwab

defoliation is very stressful for a tree. Don't know if either of the species you mention are vigorous enough for defoliation. Get to know your trees better first. Defoliation is usually to increase ramification on close to "finished" trees as well as then to decrease leaf size. But, a defoliated tree must be very healthy. You might want to try a partial defoliation, like one branch that you maybe don't need anyway.

Suggest you try to find articles about the species in question to see if they can be defoliated. Even some maples can't take it.

__________________
David Yedwab

mgodbee

I certainly don't have tons of experience, but I don't reccommend defoliating at all, especially in the same range as a repot. To me, I just pull off the big leaves and let the pot and sun do the rest... Some will differ with that though.. I have defoliated before though, and have not seen alot of difference. I actually got the opposite result with a ficus retusa. The leaves came back bigger...

redfokker

Thanks for the input. I have noticed that the internode length on both trees seems kind of far apart. I have been reading articles and publications about pinching back growth. I have been kind of reluctant to mess with these trees since they seem so happy right now. The biggest length of the internodal space is on the Katsura, almost two inches in places.

Attached Images

april katsura 400x.leaves.jpg (34.5 KB, 9 views)

__________________
REDFOKKER
Albany, Oregon Zone 7

Vance Wood

I do not grow Linden and I am not familiar with Katura(?). I can tell you that you never defoliate a Linden it will kill them. As to the other tree make sure you get advise from someone who has one.

As to the reason to defoliate. This would be better posted in the Bonsai Myths category but it is appropriate here. The early bonsai books taught that defoliation was the path to reducing the size of leaves. However that is not why defoliation was done; neither should it be done for that reason. Defoliation was done to increase ramification and reduce inter-node distance. See, that's why the books said it reduced the size of the leaves, now I am left with explaining what the heck I'm talking about.

Ramification is the number of small branches at the ends of the large branches, inter-node distance is the space between groups of buds on a shoot or small branch. The greater the ramification the smaller the leaves and the shorter the inter-nodes. You can understand this by looking at it mathematically. If you assume that a tree at any given time has E amount of energy to work with during a given growing season, and under normal circumstance B amount of buds to service, it will produce X amount of new growth at a normal level. X being the total number and size of the new leaves and the length of the inter-nodes.

At the time we decide to defoliate it is with the understanding that the tree will respond to this kind of treatment. It is surprising that there are not that many trees that do well with this so be careful. When you defoliate a tree understanding that the tree needs leaves to survive and grow, the normal response is for the tree is to make new leaves. Immature buds designed for next year become active, but not at the level as the growth they are attached to. In essence you have taken X and increased it by however many new buds have opened and started growing. So you have changed the equation. E (more or less a constant) divided by B (now increased over normal) B2 will yield X, the number of leaves and their associated size. However now X is the product of B2 therefore; though X will be greater than it would normally be the size and length of the growth produced will be smaller because the amount of E(the tree's) energy is distributed over many more available locations.

You can easily see this if you attach multiple hoses to the same water source. The amount of water coming out of the spigot does not change, usually, but as you increase the amount of locations that water pressure has to service the amount of water coming out of the end of the multiple hoses diminishes, though the volume of all the hoses together will still produce the same amount of water that issues from the spigot.

In short defoliation causes the tree to use the same amount of energy it had available for ten new buds to function by growing twenty to thity new buds. This causes everything in those thirty new buds and shoots to be smaller because the tree's resources are spread thinner.

__________________
The only finished bonsai is a dead one; me 1992 MABA Des Moines Iowa

eminart

Thanks Vance. This isn't my thread, but I've been a little fuzzy on the defoliation issue myself. You helped to clarify it a bit. So, what happens the next year to the same tree? The leaves are little bigger again right? And the year after that they're back to normal size? Or, if all things are balanced, (pot size, sun, water, pruning,etc.) can the leaves be kept relatively small without a frequent need for defoliation? None of my books go into much detail about this. They briefly describe defoliation but not in a long term sense.

thanks again,

-scott

__________________
"I want life in every word
to the extend that it's absurd....." -- the postal service

Vance Wood

Keeping a tree confined to a container is usually enough to influence the size of leaves significantly, but again that is species Dependant. You should never defoliate more than two seasons in a row or you will weaken a tree. The next seasons leaves will be shorter. After this the defoliation process usually is selective, you remove the largest leaves and mostly those on the outside parameters of the tree leaving the inner leave to strengthen those buds that don't get enough light. It is a complected process.

__________________
The only finished bonsai is a dead one; me 1992 MABA Des Moines Iowa