Osteospermums, similar to snapdragons and pansies, are most often grown as cool-season annuals that pack a fragrant punch. Some varieties are hardy to Zones 10-11, but it’s best to grow them in mild climates. In many instances, the plants will take a break from blooming during the hot summer until cool nights resume in fall.
Ideally, osteospermum prefers full sun; the more light you can give them, the better they will bloom. Osteospermum prefers evenly moist, well-drained soils. However, too-wet soil is a sure way to stress out, and even kill, osteospermums. Once they are established, they are fairly tolerant of drought. Remove any spent blooms and fertilize regularly to keep them blooming and looking their best.