Osteospermums are a member of the Asteraceae family, just like Shasta Daisies and Zinnias. They like sunny, well-drained conditions and are considered a tender perennial. This means that in an area where the winters are frost-free, Osteospermums will live and grow without protection from the cold. The cultivars with the dark blue centers will stand some frost, and will be perennial in gardens further north.
African Daisy is another name for Osteospermum. The plant originates in South Africa and is sometimes called Cape Daisy. A wide range of colors are available with pinks and purples being the most common. New cultivars are being introduced all of the time with the palette ranging from pale yellow and orange, to white, pink and purple. The petals vary from smooth and regular to dipped and spoon shaped.
The Osteospermum does best when situated in sunny areas. The flowers open fully in direct sun, and close each evening. They bloom best when the nights are cool. During periods of the summer when the nights are quite warm, there will be a period of reduced blooms. When the nights cool off, they will perk back up and put on a fresh show.
Most Osteospermums are hybrids, so saving seed is not recommended. The resulting seedlings will not resemble the parent plant. If it does not matter what color or shape that the flowers are, then the best way to start seeds is to sow them on top of well drained seed starting mix. These plants need light to germinate and prefer cool temperatures. The common practice of putting seed trays on a heat mat isn't desirable for these plants. They need cool temperatures in the 64 to 68 degree range.
The best way to propagate Osteospermum is to take cuttings from established plants. Here is an example of how to take and root cuttings.
Prepare a tray of sterile seedling mixture by damping it with warm water until it feels like a well squeezed sponge. Mix that is too wet will promote the growth of mold, and the cuttings will rot before they root.
Select several good side shoots of your Oseospermum. Either pinch the buds out, or select shoots where no blooms have formed yet. The cuttings do not need to put energy into forming blooms before they form roots. The cuttings need to have at least two sets of leaf axils and be a two to three inches long.
Cut the shoots with a sharp knife or scissors just below the leaf node, and strip the leaves off of that joint.
Dip in rooting hormone to promote the growth of new roots. Most rooting hormone has an anti-fungal also. It helps prevent the cuttings from rotting.
With a pointed instrument, make a hole in your mix that is just a little bigger than the stem. Carefully place the stem in the hole and firm the potting mix around it. The cuttings will root best with temperatures between 60 and 68 degrees Fahrenheit. Put them in a bright area, but out of direct sunlight. Grow-lights indoors are fine, or on a sheltered porch. The cuttings should form roots in 3 to 4 weeks. When they start to put on new growth, they have rooted, and can be hardened off for planting in the garden. These cuttings will branch out and form side shoots if they are pinched back after a couple of weeks.
Osteospermums will grow happily in the garden or in containers. They only ask to be kept well watered. Make sure that the growing medium is well drained though, as they do not like wet feet or soggy conditions.
A general purpose fertilizer for blooming plants is helpful every month during growing season, and dead-heading will promote continuous blossoms. By pinching out the growing tips a couple of times during the summer, a compact, bushy plant will result.
These are plants that can survive under harsh conditions by wilting and dropping top growth. During periods of drought, they will appear dead, only to spring to life once the rains return.
When choosing Osteospermums at the garden center, select plants that are compact and well branched. When planting them, dig the hole the same depth as the roots are, and place your transplant at the same level. Firm the soil around the plant and if mulch is used, leave an area between the stem and the mulch.
African Daisies are a good value in the garden, rewarding you with abundant blooms throughout the summer and fall. All they ask is for a sunny spot with regular watering. They thrive when pinched back, and the cuttings can be turned into more plants quite easily. They are a lovely little flower that is becoming more popular each season and deserve to be included in the garden