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.

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