Osteospermum, commonly known as the African Daisy, is a genus of flowering plants within the Asteraceae family. Native to South Africa, these plants are prized for their vibrant, daisy-like flowers that close at night and on overcast days. They are tender perennials, typically grown as annuals in most of the USA, except for the warmest zones (10-11) where they can survive winter. Their growth habit ranges from low-growing, spreading mounds to more upright forms, making them versatile for containers, borders, and ground cover.
From a botanical and horticultural perspective, the most common Osteospermum varieties available to American gardeners are not separate species but are primarily hybrids and selected cultivars bred for specific traits. These are often grouped into series developed by plant breeders.
The **4D™ Series** is notable for its unique "spoon-shaped" or "quilled" petals. The florets (often mistaken for petals) curl inward along their length, creating a tubular, spoon-like appearance. A popular cultivar is 4D™ Pink, which offers a textured, three-dimensional look to the flowerhead. The **Serenity Series** is one of the most widespread, valued for its compact, well-branched growth habit and prolific flowering. It comes in a wide array of colors, including white, purple, and orange, providing a uniform appearance in mass plantings. The **Voltage Series** is known for its larger flowers and heat tolerance, a crucial trait for gardeners in the southern USA. The flowers maintain their color intensity even in hot summer conditions.
The primary distinctions between varieties lie in their flower morphology, plant structure, and environmental adaptability. Flower forms include the standard daisy type with flat, radiant florets, semi-double forms with extra layers of florets, and the distinctive spoon types. Colors span from pure white and cream through vibrant shades of yellow, orange, pink, purple, and deep burgundy, often with contrasting central disks. Plant habit is another critical factor; some varieties like the **Asti™ Series** form compact, uniform mounds ideal for the front of a border, while others, like many in the **Serenity Series**, have a slightly trailing habit perfect for spilling over the edges of containers and hanging baskets.
For cooler summer climates in the Pacific Northwest and Northern states, most standard series like **Serenity** and **Sundance®** perform exceptionally well, flowering profusely in the moderate temperatures. For the intense heat and humidity of the Southern and Southwestern USA, heat-tolerant varieties are essential. The **Voltage Series** and **Soprano® Series** are bred specifically to withstand high temperatures, continuing to bloom through the summer where other varieties might falter. In California and other Mediterranean-like climates (USDA zones 9-10), Osteospermum can be treated as a perennial, with varieties like **Osteospermum ecklonis** and its cultivars thriving year-round.
