- Mimosa trees are a member of the Fabaceae family and are a popular ornamental tree in the home landscape. Also known as silk trees and Albizia silk trees, these beauties have a lovely feathery habit with wispy pink to rose aromatic flowers. Ideal for USDA planting zones 6 through 9, this tree provides light shade and adds a lovely burst of color amongst other deciduous or evergreen trees, or when used as a specimen. The fringed foliage ranges from bright green to chocolate brown, depending on the variety. - Store the Seeds. - Put the mimosa seeds in a paper or cloth bag and store them until spring in a cool, dry location. Avoid using a plastic bag as it will trap moisture and cause the seeds to rot. - Prep the Seeds. - Prepare the mimosa seeds for sowing after the last spring frost. Rub the end of each seed with a nail file until a small, pale spot appears on the hull. Then soak the seeds in hot water for 24 hours before sowing. - Sow the Seeds. - Fill individual 5-inch biodegradable pots with a lightly moistened mixture of half sand and half loam. Sow one seed in each pot at a 1-inch depth. Spread a 1/4-inch-thick layer of sand over the soil. - Move the Pots Outside. - Set the pots outdoors against a south- or west-facing wall with full sun. Provide 75 F bottom heat with a propagation mat if the weather is cool and light shade at midday if daytime temperatures rise above 90 F. - Monitor the Moisture. - Carefully monitor the moisture level of the soil. Water to a 2-inch depth whenever the top 1/2 inch of soil dries out. Avoid overwatering or letting the soil dry out completely, which will cause the mimosa seeds to fail. - Watch for Germination. - Watch for germination one to three weeks after sowing. Grow the seedlings under the same conditions as during germination until they reach 3 inches in height and produce several mature leaves. - Transplant the Trees. - Transplant the mimosa trees into a permanent bed in autumn at least six weeks before the first frost. Choose a planting site with full sun at least 20 feet away from structures, utility lines and other trees. Plant multiple mimosa trees approximately 20 feet apart. - Mimosas thrive in a variety of soil types and textures and may be found growing along roadsides or in abandoned fields in poor to average soils in full sun, although they can tolerate partial shade. Until the trees are well-established in your landscape, apply water when the top couple of inches of soil are dry to the touch; reduce water in winter. Suppress weeds by applying approximately 3 inches of organic mulch evenly out to the tips of the branches, but don't allow the mulch to touch the base of the tree. Withhold fertilizer for the first two to three years and then have the soil tested to determine if fertilizer is necessary.