Solenstemon scutellarioides, commonly known as Coleus, is an herbaceous perennial native to Malaysia and Southern Asia. Coleuses have been useful plants since Victorian times and have thousands of cultivars. Although they are warm temperature plants, they are often used as bedding plants and container plants worldwide. There are so many cultivars, it is very hard to choose which ones to plant. The plant in the photo was a cutting I received about a year ago. Having been used to grow the Fairway mixes for years, I had no idea how the plant had changed. Today cultivars have many brilliant colors, except for blue. They are easy plants to grow whether in the landscape or in containers. Plants are perennial in USDA zones 10-11.
Blooming: Coleus can bloom at any time of the year. The blue flowers can be very showy depending on which cultivar is selected.
Culture: Solenstemon scutellarioides needs partial shade to full shade and a moist, rich soil mix. Plants grown in full sun here in Oklahoma tend to wilt very badly during our hot summers. In containers, we use a soil mix consisting of 2 parts peat moss to 1 part loam to 1 part sand or perlite. For each 0.01 cu yards of soil mix we add 1 cup of 14-14-14 Osmocote slow release fertilizer, 1 cup of hydrated lime to adjust pH, and we add 2 tbs. of Micromax micronutrients. This makes a very rich soil mix. The plants are kept moist and we fertilize them monthly with a balanced fertilizer. During winter months in the greenhouse, we restrict the water somewhat; plants should not be allowed to wilt.
Propagation: Solenstemon scutellarioides is propagated from cutting and from seed. There are many cultivars and seed companies that sell coleus seed. Seed germinates in 7-14 days from sowing at 72-75°F (22-23°C).
Solenstemon scutellarioides was featured as Plant of the Week February 27-March 5, 2009.
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.