Othonna is a genus of more than 100 African plants in the family Asteraceae. These are evergreen or deciduous geophytes, dwarf succulents, or shrubs concentrated in the Western Cape province of South Africa and southern Namibia. A few species occur in summer rainfall parts of southern Africa. The genus is closely allied to Senecio and can be distinguished principally by details of the involucre.
The form or habit of Othonnas is very diverse. Leaf diversity is also notable in this genus. A few species possess highly succulent leaves (Othonna capensis and Othonna sedifolia), but most have bifacial leaves that are only slightly succulent. Size and shape are variable, with most species having from 0.4 to 4 inches (1 to 10 cm) long leaves.
The bright yellow (occasionally white or purple) flowers are the most distinguishing characteristic of the genus, and the flowering times differ from different species. Some bloom just before the beginning of their summer rest, and others bloom after fall growth begins.
Growing Conditions and General Care
Othonnas have a variable range of habitats, some grow in very hot arid regions, but they avoid the intense desiccating rays of the north and west sun, growing between rocks in southern slopes. On the contrary, a few species grow in direct sunlight in arid situations that become very hot and dry and saturated for a few weeks during their growing period. All Othonnas grow in very open situations with plenty of free air circulation.
The fleshy leaves and daisy-like flowers make Othonnas excellent in a desert or rock garden (where hardy) or indoors as houseplants or greenhouse specimens.
Othonnas tend to be fairly hardy, but as Othonna cacalioides, some can be extremely difficult to grow in cultivation. Keep them in flat pots if you do not give them the right conditions and space to develop the radicular system. In summer, protect plants from direct sunlight. They like to be moist, fresh and have plenty of light in the growing season. They do not like temperatures below 50 °F (10 °C).
In the warmer months, Othonnas go into their dormancy period. Stop watering, and place them in a shaded, cooler area, away from direct sunlight, relatively dry, and with good air circulation. When nights cool down in the fall, the plants may start growing on their own, but a good soaking will help them to leaf out.
A typical succulent soil mix should be suitable for growing Othonnas, but additional drainage material would be recommended.
Propagation
Start seed in spring at 64 to 70 °F (18 to 21 °C). Plants can also be propagated from basal or semi-ripe cuttings in late summer using bottom heat.
Links
- Back to genus Othonna
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus