Issue: November 14
You can start a mimosa tree from seeds?
Q. I have seen a beautiful tree that I like. It seems to be a shade tree. I love it and want to grow it. I am sending you some leaves and seeds so you can identify it for me. Please tell me when to plant these seeds and how to care for them.
A. The plant sample you sent was pretty crumbled by the time I received it. It is a good idea to place soft plant material (leaves, flowers, seeds) between two pieces of cardboard when mailing them. However, this time there was enough to determine that the tree you are asking about is called mimosa. It has many very small leaflets, a feathery pink flower in early summer, and the thin bean pods. The flowers are nicely fragrant and the shade cast by this tree is also very pleasant.
You can plant the seeds where you want the tree to grow, or you can start them in a pot and transplant them. The easiest method is to prepare a "flower bed" in the place you want the tree to grow. These seeds may benefit from "scarification," or scratching them with a nail file before planting. This will help water enter the seeds and start their growth. Plant the mimosa tree seeds now and in the spring plant flowers in the same bed. As you water the flowers, the mimosa seeds will also receive water and begin to grow. Plant many seeds in one area and as they begin growing, cut out all but the one or two best trees in the bed to become your permanent tree. When the trees become large, do not plant flowers at the base to avoid damaging the roots, but for the first year or two you can continue to plant flowers at the base of the tree. By starting the tree in the location you want it to grow; you will not need to worry about any damage in transplanting.
If it is necessary to start the seeds in a pot and transplant later, you can do so. Scarify the seeds as described above. Plant them in pots with good potting soil and put them outside for the winter, or put the seeds on moist paper towels in sealed plastic bags. Store these bags in the refrigerator for 6 to 8 weeks, then take the seeds out and plant them in the pots. The seeds should sprout in the spring and be ready to transplant next fall.
In a few years, you should have the flowering shade trees you have seen elsewhere growing in your landscape. Once growing in the landscape, these trees will need to be irrigated twice a month during the growing season, once a month during the winter (dormant) season.
For more gardening information, visit the NMSU Extension publications World Wide Web site at http://aces.nmsu.edu/pubs/_h.
Send your gardening questions to:
Yard and Garden, Attn: Dr. Curtis Smith
NMSU Agricultural Science Center
1036 Miller Rd. SW
Los Lunas, NM 87031
Curtis W. Smith, Ph.D., is an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. NMSU and the U.S. Department of Agriculture cooperating.