Rhus undulata or Kuni Bush is a dense evergreen shrub or small tree native to South Africa. Leaves are trifoliate, dark green with a shiny lacquered look. Leaflets are obovate, small and very sticky. In nature, the shrubs will reach from 3 to 10 feet (1-3 m) tall and wide. The bark is gray-brown, with young twigs being reddish in color. Older growth may or may not have spines. Plants grown in containers will be smaller than in nature, which makes them great Bonsai subjects. They are very easy to grow and are hardy in the landscape in USDA zone 9-11.
Blooming: In the greenhouse, we usually have 2 flushes of flowers, one in the spring and one in late summer. Flowers are borne in terminal inflorescences, star shaped and very small.
Culture: Rhus undulata needs full sun to light shade with a very well-drained soil mix. We use a soil mix consisting of 1 part peat moss to 1 part loam to 2 parts sand with small gravel added to ensure good drainage. Plants are watered and allowed to dry before watering again. We fertilize the plants once during the spring with a balanced fertilizer. After the summer blooming period, we trim and repot plants as needed. This helps in controlling size. During the winter months, the plants are placed in the cool room where nighttime temperatures do not fall below 48°F (9°C). Water is restricted during this period.
Propagation: Rhus undulata is best propagated by seed. We obtained seed from Silver Hill Seeds in South Africa. Seeds were treated with a 45 minute soak in sulfuric acid before sowing. Seeds germinate in 30-60 days after sowing.
Rhus undulata was featured as Plant of the Week October 16-22, 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.