1243 Osteospermum sppCommon Names: African daisy,Cape daisy,Blue-eyed daisy,osteo,osteospermum Family: Asteraceae (aster/daisy Family)
There are some 70 wild species of Osteospermum, only a few of which are commonly found in cultivation. However, gardeners have many hybrids and cultivars to appreciate. Most African daisies and their cultivars are evergreen subshrubs with semi-woody stems. They have daisylike flowers, 2-3 in (5-8 cm) across, with brightly colored rays and discs that often are of different colors. Some have ray florets that are spoon shaped. Most plants reach mature sizes of 12-36 in (30-90 cm) in height and 12-24 in (30-60 cm) across. The leaves are alternate, linear to obovate, and may be entire or toothed.
Osteospermum ecklonis is a 3-5 ft (90-150 cm) tall evergreen semi-woody subshrub with flowerheads 3 in (8 cm) across. The rays are white with bluish streaks underneath and the disc florets are reddish purple. O. fruticosum is an evergreen perennial that spreads to cover large areas. Flowers usually are pale purple, but other colors are available. O. jucundum (= O. barberiae) has ray florets that are white with purple bases and discs that are violet. O. jucundum ‘Compactum’ (white rays) and ‘Compactum Blackthorn’ (purple rays) are wide spreading dwarfs, that reach only 6 in (15 cm) in height.
Many hybrid cultivars from these three species and others are available. The ever popular and very distinctive Osteospermum ‘Whirligig’ has white rays with blue backs that are crimped midway and widened again at the ends to become spoon shaped. It has blue disc florets. Other African daisies with spoon shaped rays include ‘Pink Whorls’ and ‘Cannington John’. O. ‘Bodegas Pink’ is smaller, to 18 in (45 cm) tall, with pinkish rays and bluish discs. Even smaller cultivars include these three with pink ray flowers: ‘Starshine’, ‘Hopley’s’, and ‘Potpourri’. O. ‘Buttermilk’ has pale yellow rays. The Cannington Hybrids have flowerheads in white, pink and purple. ‘Silver Sparkler’ has variegated foliage with snow white rays and dark blue centers. Seed races (cultivars that come true from seed) include ‘Dwarf Salmon’ and ‘Tetra Pole Star’.
The various species of Osteospermum are native to Africa, especially South Africa, and also parts of the western Arabian Peninsula. The wild species grow in grasslands, at the edges of forests and on rocky hillsides.
African daisies are not the easiest flowers to maintain. Light: African daisies like a position in full sun, but benefit from afternoon shade during hot weather. Moisture: African daisies do best in a well drained soil with regular watering. They do not like clayey soils and will not tolerate waterlogged soils at all. The roots will rot if the soil or potting medium is not well drained. Most cultivars can tolerate considerable drought. They may go into dormancy during very dry periods, but come back to life when regular watering resumes. African daisies do best in slightly acidic soils. They tolerate poor, sandy soils, and many cultivars seem to have some salt tolerance as well. Hardiness: USDA Zones 9 - 11. Only a few species and cultivars of African daisy can survive winters in zone 9. Osteospermum ecklonis and O. jucundum have been known to survive winter temperatures as low as 14°F (-10°C). The cultivar ‘Weetwood’ can handle occasional winter temperatures even lower. Most of the African daisies, however, do not tolerate frost or freezing temperatures. In temperate climates you should take cuttings before the first frost and overwinter them indoors. Most African daisies flower best when nighttime temperatures are a little cooler. If nighttime temperatures stay high, the plants may stop flowering. They do not do well in areas with hot, humid, rainy summers. Propagation: Softwood cuttings are easy to root. Seed may be sown in spring when temperatures are above 64°F (18°C). In frost-free areas seed can be sown in situ. Otherwise, start seed indoors 6-8 weeks before the last frost. African daisies usually bloom their first year from seed and thus can be grown as annuals. Of course, most African daisies in cultivation are hybrids and cannot be expected to come true from seed, so you never know what you will get. On the other hand, the true species, such as O. ecklonis and O. jucundum, can be grown from seed, as can the cultivars that are sold by seed (that is, seed races).
African daisies are used in flower beds and borders, often in botanical gardens and public parks. They are grown in the sunny front of shrub borders and smaller ones are useful in rock gardens. Under ideal conditions masses of African daisies will bloom for weeks on end. Some of the shorter varieties are planted along highways where they spread by rhizomes and beautify miles of roadside. African daisies are popular potted plants, placed in a sunny position on the deck or patio. Just be sure the containers have excellent drainage.
Many of the African daisy cultivars will flower almost continuously throughout the summer if kept well watered and fertilized. Others flower twice, once in the spring and again later in the summer. In any case, it helps to dead-head spent flowers. It is also good to prune back long stems, which will cause more lateral stems to develop and make the plant more bushy.
Steve Christman 8/30/15