Withania somnifera, or Ashwagandha, is native to drier parts of India and the Old World. It is a perennial herb that reaches about 6 feet (2 m) in nature. The plants contain the alkaloids withanine and somniferine, which are used to treat nervous disorders, intestinal infections and leprosy. All plant parts are used including the roots, bark, leaves, fruit and seed. They are hardy in USDA zone 10.
Blooming Time: In the greenhouse they flower in the late fall and winter. Orange fruits in persistent papery calyxes follow the small greenish flowers.
Culture: Withania somnifera need full sun to partial shade with a well-drained slightly alkaline soil mix. Plants do best when the soil pH is 7.5-8.0. We use a soil mix consisting of 2 parts sandy loam to 1 parts sand. The plants are allowed to dry thoroughly in between waterings. In containers, too much water causes root rot. Plants are fertilized once during the year with a balanced fertilizer diluted to ½ the strength recommended on the label.
Propagation: Withania somnifera are propagated by division, cuttings or seed. Seed is the best way to propagate them. Seed sown on moist sand will germinate in 14-21 days at 68° F (20° C).
Withania somnifera was featured as Plant of the Week December 20-26, 2002.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.