Mimosa trees are also called silk trees or silky acacia. They look as if they belong in a tropical environment but are actually quite hardy. They grow to a height of 25 feet and sport hot-pink flower clusters. Mimosas do well in almost any kind of soil and can even tolerate drought-like conditions. Pruning them will help shape the tree as well as keep it healthy.
Decide whether you want the mimosa tree to be a single-stem or multi-trunk tree. If you want it to have a single, leader stem, clip any competing stems with pruning shears while the tree is young. For more than one trunk, allow the other stems to grow.
Prune the silk tree in the spring, if necessary. Cut last year's growth back so the stems only have five or six buds. This will control the growth and spread of the tree.
Remove dead limbs as you notice them to keep the tree healthy. The wood tends to be brittle and weak, causing accidental breakage. Follow the branches into the center of the tree and clip them off where they meet healthy ones at a V-shaped joint. If they are too thick to handle with shears, use a pruning saw.
Pull seedlings and small plants as soon as they are big enough to grasp by hand, but before they flower. Mimosa trees can be very intrusive, dropping seeds and causing hundreds of new seedlings.