Question
I have a large mimosa tree (approx. 20'h x 20'w) that needs a serious pruning as it's size is starting to bring it down.  How far back can I prune it, I was thinking about 6' and when can I do it.

Answer
The best time to prune trees is early fall, late winter, or early spring. As some gardeners like to say, there really is no bad time to prune. The exception would be flowering trees and bushes since you want to avoid pruning branches with buds. For these plants you should prune once they drop their flowers. Also avoid the two week period before your first expected frost to prevent damage to freshly pruned branches and limbs.

The general rule of thumb is that trees should never be pruned more than a third. Therefore, if your mimosa is 20 ft. high, 6' sounds perfect.

I hope this answered your question. Please write again if I can ever be of assistance.

Regards,

Mike