My blue lilac bush has always grown large, coarse, and very often malformed leaves. It also gets a strong case of fungus every year. This year I really thinned the leaves/branches out to make sure it would get good circulation. It's actually doing a little better, but it's still growing large ugly coarse and malformed leaves. I'm planning on moving this shrub to another location this coming fall or Winter before Spring. When I do that, can I cut the tap root, kind of like bonsai, to try to slow it down and have it grow smaller and less coarse leaves? The shrub is already trained into a three branch tree with mature bark bearing trunks. Would playing with it's tap root like bonsai kill it or help to lighten up it's monster malformed leaf formation. The lower and smaller branches grow nice, lightweight and well formed leaves, but the major stem lines again are these coarse and malformed leaves.