Mimosa trees (Albizia julibrissin) are hardy in U.S. Department of Agriculture plant hardiness zones 6 through 9. These trees are fast growers and can reach their mature heights of 30 to 40 feet in about eight years. Mimosa, a deciduous tree with fern-like leaves, is also called the silk tree, because it produces soft pink flowers that resemble strands of fine silk. You can propagate mimosa trees from branches, but take care when you transfer the rooted cutting into a bigger pot, and then transplant it into the ground one year later, because the mimosa can go into shock.
Cut a 4 to 6-inch stem of the mimosa tree late in the spring. Make the cutting underneath the section where the leaves are attached to the stem. Choose a branch that did not bloom.
Fill a 4-inch pot with well-drained potting soil. Water the soil until the water comes out of the drainage holes at the bottom.
Remove all but the top two or three leaves at the top of the mimosa's stem.
Dip the leafless end of the stem into a glass of water. Shake the stem to remove the excess water.
Stick the wet stem into rooting hormone. Tap the stem to remove the excess rooting hormone.
Insert the stem with the hormone rooting powder into the soil and firm the soil around it gently. Place the pot into a plastic bag and tie the bag shut.
Position the pot in a sunny window, out of direct sunlight. Keep the mimosa in a place where the temperature remains around 75 degrees Fahrenheit.
Open the bag daily to check the soil for moisture. Keep the soil moist, but not soggy.
Test the cutting for roots after three weeks, by pulling gently on the stem. If the stem moves easily, then the roots have not formed yet. Roots have formed when there is resistance when moving the stem.
Remove the plastic bag when roots have formed and continue to grow the mimosa in the smaller pot for two months. Keep the soil moist, but not soggy.
Transplant the mimosa carefully into a 1-gallon pot and continue to grow the mimosa in a protected area in your home or greenhouse. After a year, it is time to transplant the mimosa into a permanent location.