Q.Why Do Some Sites Say That Silk Mimosas Are A Threat To Other Native Plants And Trees?
Are they really that bad? Some even discourage intentional planting. I think they’re beautiful!
Certified GKH Gardening Expert
I think they are beautiful, too, and that is one of my fond memories of my grandmother's house when I was young. They are considered short lived, with weak wood and a bad habit of reseeding groves into disturbed areas where they shade out native species. There are a number of trees and shrubs that are considered a threat to native species. Another is the non-native burning bush, which I see everywhere. It is reseeded with help from birds eating the berries and is considered invasive.
https://www.gardeningknowhow.com/ornamental/trees/mimosa/mimosa-tree-weeds.htm
https://www.gardeningknowhow.com/ornamental/shrubs/burning-bush/burning-bush-control.htm