posted 19 hours ago
Here in SC, I've cut them to the ground mid-summer and they bounce right back the next year. This has worked on trees 3+ inches in diameter, maybe 5+ year old trees. In fact, in the past, we were trying to kill them! (In our area they are considered weedy/invasive, as you mentioned.)
I'm no longer at war with the silk trees, but I'm very aggressive with harvesting them. They're so rugged here I cut poles and leaves (green mulch) any time it's convenient. I cut them back if I notice flowering, since I do want to avoid them spreading. (There are plenty of mimosa seeds spreading onto the property from elsewhere, very abundant here)
If I wanted to be more gentle to the tree, I would cut no more than 1/3 in a year, and I would avoid peak summer heat. That's how I treat some of my other chop-and-drop trees.