The Silk tree, so named for its panicled flower, was originally brought to this country in the 1700's as an ornamental specimen. These Silk Mimosa trees for sale can reach heights of 40 feet and can grow to 40 feet in width. Mimosa trees have smooth gray bark and hot pink flowers that bloom spring through summer. The leaves of the trees are 5-8 inches long and 3-4 inches wide and have a feathery appearance.