Osteospermum

( os - tee - oh - SPUR - mum )

At-A-Glance Information

Known commonly as African Daisy or Daisybush, this genus of perennial flowering plants includes species which need full sun and moderate to regular water to bloom and perform well. They are woody-based and have a mounding, trailing habit, flowering more profusely in cooler weather. Natives of South Africa, these flowers only open in sunlight, otherwise staying closed. These plants look great when massed along pathways or driveways, in borders, rock gardens, or containers. They are included in many different landscape styles, including cottage, informal, and pollinator gardens.

Osteospermum Species and Varietals

The genus Osteospermum includes 74 species and is a member of the plant family Asteraceae. It is closely related to the genus Dimorphotheca, and some species of Osteospermum have been transferred to that genus. Plants in this genus are also related to those in Calendula, Bellis (Daisy), Helianthus (Sunflower), Zinnia, and Aster. The best growing zones for African Daisy are USDA hardiness zones 9-11 or Sunset growing zones 8, 9, and 12-24, though this varies somewhat depending on the species grown. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Osteospermum calendulaceum (Oligocarpus calendulaceus, Calendula parviflora) (Stinking Roger, Boeboebossie)
These flowering plants are native to South Africa, and is considered a weed in some areas of the globe). Blooms are yellow and present almost year-round in some climates. Individual plants grow up to 16 inches tall when mature, and produce decumbent stems and small yellow flower heads. This species is considered invasive in Southern Australia, Hawai'i, and California (United States).

Osteospermum spp. Hybrids (Hybrid African Daisy)
This group of flowering plants come in many colors and flower shapes, and have been bred to resist diseases like powdery mildew. Cultivars are listed and described below:

Symphony Series
To 8-12 inches tall with a mounding habit. Flowers have dark blue centers.

Sunny Series
Compact, to 12 inches tall with a wide variety of colors and flower shapes.

'Nairobi Purple'
('African Queen')
This plant reaches 18-20 inches tall and has white to purple flowers.

'Burgundy'
This plant reaches 18-20 inches tall and has bright purple flowers.

'Brightside'
White flowers have a blue eye.

'Highside'
This bicolored blooming plant has white and pink flowers.

'Riverside'
With yellow flowers.

'Wildside'
With dark purple blossoms.

Osteospermum moniliferum (Chrysanthemoides monilifera) (Boneseed, Bitou Bush, Bietou, Tick Berry, Bosluisbessie, Beskusbietou)
These plants are native to South Africa, and have become a weed and invasive species in Australia and New Zealand. The species forms a spreading shrub or small tree to just under 10 feet tall. Flowers are yellow and daisy-like, blooming in clusters at branch tips. These shrubs are considered highly invasive in Australia, New Zealand, Chile, Sicily, and southern France.

Caring for osteospermum

Osteospermum plants can be grown either from seed direct sown in the garden (or started indoors) or purchased as nursery specimens. They will reseed freely, spreading over time, and should be planted in a space in the garden where this tendency will not be an issue. African Daisies should be planted in a spot in the garden that receives full sun; ideally, they should receive between 6 and 8 hours of direct sun each day for best flowering. They like soil that is sandy and well-draining, with a moderate amount of fertility and a pH of between 5.0 and 5.7. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost and sand before installing flowers. Apply a thick layer of mulch around the planting area to suppress weed growth, maintain soil temperatures, and increase soil moisture retention.

Water new plantings regularly as they establish a strong root system. Mature plants are considered to be quite drought tolerant, though they do benefit from occasional waterings in summertime in areas with low rainfall. Each year in springtime, apply a 2-inch layer of organic compost around the planting area to improve soil structure, drainage, and nutrient load. This feeding should be sufficient to provide these flowers with enough nutrients to get through their growth and flowering seasons with ease. Pruning is not necessary, but if any foliage is becoming unsightly, it can be removed at any time during the growing season. Spent flowers can be removed to neaten up the look of plants and encourage more blooms to pop. If propagating these plants via seed, the flowering stalks will need to remain and seed heads will eventually mature, providing seeds for the next generation of plants. Osteospermums are perennial plants that can survive in the landscape for 5 to 8 years on average before becoming overly woody and requiring replacement. In cool zones, they are treated as annuals, pulled and composted at the end of the growing season and replaced in the next with new plants.

Caring for Osteospermum in Containers
These flowering shrubs are wonderful in the ground, but can also be grown in containers. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Osteospermum plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Osteospermum can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your African Daisy plant, follow the instructions below:

Propagating Osteospermum by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 3-4 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new flower.

Propagating Osteospermum by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed heads on African Daisy plants are pretty easy to find, they're left behind after flowers have faded. Once they have dried out, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside, or they can be manually opened. Once seeds have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray on the soil surface and cover them with a light layer of soil. Water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7 to 21 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Osteospermum plants produce seed pods that turn brown and brittle once mature. They can contain between 15 and 30 seeds.

Osteospermum seeds are small, elongated, and typically dark colored.

Problems and Pests

Certain Osteospermum species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Osteospermum plants are typically quite resistant to pest and disease issues in the landscape, making them easy to care for. However, from time to time, they can suffer from issues with the following: