Delosperma nubigenum aka Yellow Ice Plant

Delosperma nubigenum is a low succulent in the ice plant family, Aizoaceae. Gardeners call it hardy yellow ice plant. Its native range runs from South Africa's Free State to Lesotho. It grows in mountain areas within this range. This perennial forms a close mat rather than an upright clump. Its creeping growth makes it useful where low cover suits the site.

Garden plants reach about 0.17–0.33 feet (0.05–0.1 metres) tall. Spread varies more across the sources. Missouri Botanical Garden gives about 1.5–1.7 feet (0.46–0.51 metres). RHS gives a broader spread of 1.6–3.3 feet (0.5–1 metre). NC State lists widths down to 0.75 feet (0.23 metres). The plant grows fast, though RHS gives two to five years to maturity. Its leaves are thick, glossy, pale green, and free of hairs. They reach about 0.1 feet (0.03 metres) long. Fall and winter bring red or bronze tones. Leaves remain year-round in mild winters, but colder sites may lose some foliage.

The yellow flowers look like small daisies and sit above the leaves. Each flower has many narrow rays around its centre. NC State and RHS place flowering in spring or late spring. Missouri Botanical Garden describes blooms from late May into fall. Chicago Botanic Garden lists a May-to-October bloom season. The length of bloom therefore varies among these garden accounts. Bees and butterflies visit the flowers, adding value to the low planting.

Full sun and freely drained soil suit this plant best. NC State also lists partial shade as suitable. Sandy or shallow, rocky ground fits its needs. It accepts acid, neutral, and alkaline soils. Established plants tolerate drought, heat, and some salt exposure. Excess water poses a greater risk than dry soil. Wet soil in winter can kill plants, so drainage matters year-round. Chicago lists USDA zones 3–9, while NC State lists 6–9. RHS rates it H5. Missouri Botanical Garden warns that St. Louis winters may require shelter and protection.

Use it as ground cover, along edges, or in rock gardens. It also suits pots, gravel gardens, banks, and slopes. Its low mat and bright blooms work well in borders. Short stem pieces root with ease, and plants need no pruning. RHS reports few pest or disease problems. Missouri Botanical Garden still advises watching for aphids and mealybugs.