Fockea edulis aka Hottertot Boom

Fockea edulis is a long-lived succulent vine in the Apocynaceae family. Kew places its native range from the Cape to KwaZulu-Natal. LLIFLE also records it in Namibia. It grows in warm, dry scrub, savannah and rocky ground. Gardeners grow it for its thick, swollen rootstock, called a caudex. This gives the plant much of its ornamental value.

The plant reaches about 10 feet [3 metres] with support. Shoots may extend to 13 feet [4 metres]. Thin stems twine around nearby plants or a frame. Other branches have a more woody form. The grey caudex has small bumps and thick, twisted roots. It can reach 1 foot [0.3 metres] across, sometimes 2 feet [0.6 metres]. Wild plants keep this base partly or fully underground. Green, oblong leaves have smooth edges. Cold, dry winter conditions can cause leaf loss. Plants in milder conditions may keep some foliage.

Small, pale green-white flowers open in late summer. They have a faint scent but little visual impact. Fruit flies pollinate the blooms. The species is dioecious, with male and female flowers on separate plants. Both sexes must be present for seed production. Grey pods hold the seeds. Seed offers the best route to new plants. Cuttings have a lower chance of success.

Grow the leafy stems in sun or light shade. Keep the caudex shaded, even when the shoots receive sun. Most soil types suit it if water drains very fast. Give ample water during active growth, with regular summer feeding. Keep it much drier in winter. Water then just enough to prevent the tuber from shrivelling. It tolerates brief, light frost down to about 28°F [-2°C]. This does not make it suited to long, cold winters. A hoop or frame helps contain its twining shoots. Without support, they can wrap around nearby pot plants.

Winter wet can cause rot, so drainage and airflow matter. Whiteflies may trouble plants in humid greenhouses. Mealybugs can also occur, while aphids may attack young stems. People have gathered the roots for food and made them into jam. That history does not mean the raw plant is safe. Its latex is poisonous, and the plant contains alkaloids. LLIFLE reports that food use needs lengthy, complex cooking. It advises against eating the plant. The supplied sources list no known medicinal uses.