Ceratotheca triloba 'Violet' - African Foxglove

Ceratotheca triloba 'Violet' - African Foxglove - Pedaliaceae

Ceratotheca triloba 'Violet' is a fast-growing, soft annual native to South and Tropical Africa. The stems are obtusely 4 angled and will reach up to 6 feet (1.8 m) tall and wide. Leaves are soft and hairy, ovate-cordate to triangular and 3 lobed to 6 inches (15 cm) long. As stated before these are very fast growing plants, when planted in containers they will bloom in 8 weeks from sowing. When grown in the landscape they should be used as a tall border or as a backdrop for lower growing plants. In Florida, the plant has naturalized. All plant parts are poisonous.

Blooming: In the greenhouse, the plants bloom in 8 weeks from seed and will continue to bloom until fall in the landscape. With a name like ‘Violet’, I expected the flowers to be violet in color. Was I ever wrong. These have a creamy white flower that will reach 3 inches (7.6 cm) long with the lower lip extended. Actually they are very showy.

Culture: Ceratotheca triloba 'Violet' need full sun to partial shade with a well-drained soil mix. In the greenhouse, we use a soil mix consisting of 2 parts peat moss to 1 part loam to 2 parts sand or perlite. The plants are regularly watered and allowed to dry slightly before watering again. We fertilize them monthly with a balanced fertilizer diluted to 1/2 the strength recommended on the label. I recommend growing them in large containers so they don't have to be transplanted much. After flowering in the fall, seed is collected for the next batch of plants. Seed is best left on the plant until the pods split. Seed then can be stored until spring.

Propagation: Ceratotheca triloba 'Violet' is best propagated from seed. Although plants will start from cuttings, it is a better overall plant from seed. Seed will germinate in 7-14 days at 70°F (21°C).

Ceratotheca triloba 'Violet' was featured as Plant of the Week July 4-10, 2008.

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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. ©1998-2017 All rights reserved.