Crassula setulosa aka Hairy Cushion Crassula

Crassula setulosa is a small perennial succulent in the Crassulaceae family. Its common name is hairy cushion crassula. Kew lists its native range as KwaZulu-Natal in South Africa. LLIFLE gives a wider range across southern Africa, reaching Malawi and Mozambique. It grows in shaded rock cracks and shallow soil pockets. Its sites include steep cliffs in woodland and mist forest.

The plant forms tight mounds of small leaf rosettes. These reach about 0.16–0.33 feet [0.05–0.10 metres] high. Flowering stems raise the height to 0.82 feet [0.25 metres]. Mounds can spread to 1.31 feet [0.40 metres] across. Slender stems branch near the base and may root as they spread. Some hang down, while their bases become woody with age. Small white bristles fringe the fleshy leaves. Leaf shape, size and hair cover vary within the species. The grey-green rosettes may turn bronze in winter. Some leaves also have red edges.

Deep red buds open into small white or red-tinged flowers. Flowers may also show pale yellow-green, pink and purple tones. Branched clusters form at the stem tips. In South Africa, flowering runs from late November through April. Small fruits called follicles follow the flowers and release fine seeds. The seeds look like dust. Plants need a cool spell to form flowers. LLIFLE reports at least one month at 15°C or below.

Light shade suits this species better than full sun. It can take full sun, which keeps growth compact. Use a gritty, porous mix that drains well but holds some moisture. Loam mixed with small gravel meets these needs. Water during summer growth, then let the soil dry before watering again. It needs more summer water than many other succulents. Reduce watering in winter to prevent the leaves from shrivelling. Feed once during growth with fertiliser at one-quarter strength. Soggy soil can cause root rot. Damp winter air can cause rot even in dry soil.

The low mounds suit rock gardens, planted walls and shallow dish gardens. The species also grows as a houseplant. Divide offshoots or sow seed to raise more plants. Offshoots can root in sand or dry vermiculite. Keep plants above freezing where possible. Dry plants may survive brief cold below −5°C. This short-term tolerance does not establish reliable winter hardiness.