Dimorphotheca pluvialis aka Cape Rain Daisy

Dimorphotheca pluvialis is an annual in the daisy family, Asteraceae. Its native range runs from Namibia to South Africa's Cape region. Gardeners call it rain daisy, Cape marigold, or weather prophet. It grows upright but also spreads into a bushy shape. Garden plants reach about 1–1.6 feet (0.3–0.5 m) tall. Their spread ranges from 0.5–1.6 feet (0.15–0.5 m). The plant completes its growth within one year.

The green leaves are simple, narrow, and broadest near their tips. Their edges have teeth or lobes. Sources differ on whether the leaves bear fine hairs. The daisy-like flower heads measure about 0.08–0.25 feet (0.025–0.076 m) across. White rays surround a central disc of small flowers. Purple marks tint the ray bases and undersides. Sources describe the centre as yellow-brown or deep purple. Flowers appear in spring or summer, extending into early autumn. They close at night and during dull weather. Insects pollinate the flowers.

The plant forms two kinds of small, brown achenes. The central disc flowers produce winged fruits that sprout first. The outer ray flowers produce flat, oval fruits. These take longer to sprout, helping the plant cope with poor conditions. Grow it in full sun with shelter from exposure. It needs fertile soil that drains well. Sandy soil and loam suit it, across a broad pH range. It tolerates drought and accepts dry to moderately moist soil. High humidity can cause trouble, while cooler summer sites suit it.

Use rain daisy in beds, border fronts, or small groups. It also suits paths, rock gardens, gravel gardens, and pots. Its white flowers fit cottage and informal gardens. Sow seeds under cover in early spring. Move young plants outdoors once frost has passed. Direct sowing in mid-spring is another option. Remove spent flowers to encourage further bloom. RHS rates it H2, so it does not survive freezing. The listed USDA range of 2–11 reflects its use as an annual.

Pests and diseases rarely cause serious trouble, but problems can occur. Watch for leafhoppers, powdery mildew, and grey mould. Keep water off the leaves to reduce rot risk. No food or medicinal uses are known. ASPCA lists it as non-toxic to dogs, cats, and horses. Researchers have studied its seed oil for possible industrial uses. These include coatings, lubricants, resins, and cosmetics.