Osteospermum, commonly known as African Daisy, is native to South Africa. This origin is a primary indicator of its inherent tolerance to challenging conditions. The species evolved in regions characterized by intense sunlight, well-draining soils, and periods of low rainfall. Consequently, modern cultivars have retained a significant degree of these xerophytic adaptations. Their physiology is geared towards water conservation, featuring small, leathery, or slightly succulent leaves that minimize surface area and reduce transpiration rates. This allows the plant to retain precious moisture during extended periods of heat and drought, making it well-suited for the climatic pressures found in many Southern states.
When confronted with the intense and prolonged heat typical of Southern summers, Osteospermum employs several effective strategies. The plant's root system, while not excessively deep, is efficient at absorbing available surface moisture. More critically, its foliage is often covered with fine, silvery hairs that reflect a portion of the harsh solar radiation, helping to keep leaf temperatures lower than the surrounding air. Furthermore, during the peak heat of the afternoon, it is common for Osteospermum flowers to close up. This behavior is not a sign of distress but a clever protective mechanism to shield its reproductive parts from desiccation and sunscald, reopening once temperatures become more moderate in the late afternoon or morning.
In terms of drought, Osteospermum's tolerance is notable but has its limits, especially in container-grown specimens. Its natural survival strategy is to enter a state of semi-dormancy during extreme drought. Growth will slow, flowering may cease, and the plant will focus its energy solely on maintaining its core vascular system. It can withstand this state for a period, and with a deep, thorough watering, it will typically bounce back vigorously. However, prolonged severe drought without any moisture will eventually lead to plant death. For optimal performance and continuous blooming through a Southern season, it performs best with periodic deep watering, allowing the soil to dry out between sessions.
From a cultivation standpoint, a plant's inherent tolerance is maximized by providing ideal growing conditions. For Osteospermum to thrive in the heat of the South, planting location is paramount. It requires full sun for prolific flowering but will appreciate some protection from the harsh, late afternoon western sun. The single most important factor is soil drainage; it must be excellent. Planting in raised beds or amending native clay soils with sand and organic matter is essential to prevent root rot, which is a greater threat than drought. A layer of mulch around the base helps conserve soil moisture and keep roots cooler. While established plants are remarkably resilient, supplemental watering during periods of extreme drought is necessary to maintain aesthetic vigor and floral display.
