Hoya caudata (Hoya flagellata)

Name, range and habitat

Hoya flagellata, described in 1940, is now treated as a synonym of Hoya caudata. The species comes from southern Thailand and western Malesia, including Borneo, the Malay Peninsula and Sumatra, where it climbs on trees in wet tropical habitat.

Growing Hoya caudata in pots

Keep the roots lightly moist in a chunky mix and a pot with drainage holes. Water when the pot feels lighter and the deeper mix is only slightly damp, before it dries out. Soak the whole root ball and drain. When growth slows, the mix may stay moist for longer. Check the deeper mix before watering.

The vines can climb a trellis or hoop, or trail from a container. Give bright indirect light and about 18–27°C, with 40–60% relative humidity and gentle airflow. Shelter the leaves from hot sun and keep temperatures above about 13°C.

Feed with balanced orchid fertiliser about every two weeks during new growth, following the label. Pause when growth stops; flush with plain water every few months. Increase pot size only for crowded roots. Replace poorly draining mix in a pot sized to the roots. Before feeding again, check the new mix’s label for added fertiliser and feeding guidance.

To propagate, root a one- or two-node cutting in lightly moist mix. Use a clean blade and wear gloves, as the sap can irritate skin. Remove lower leaves and keep other foliage above the mix. Provide warmth, indirect light and humidity with ventilation. Hold any cover off the leaves and pot into airy mix once rooted.

New loss of firmness, root decline and mite damage

• Leaves become limp or start to shrivel: Mature leaves are naturally leathery and should feel firm. Check whether the mix around the roots is dry. If the root ball is dry, water thoroughly and drain. If the leaves still wilt after watering, inspect the roots. Avoid repeated watering while the roots are still wet.
• Leaves stay limp or turn yellow in persistently wet mix: Persistent wetness can damage roots. Drain trapped water and inspect roots if decline continues. If you find a small amount of root rot, use a clean, disinfected tool to cut the soft roots back to firm, healthy tissue. Throw away the rotten roots and old mix. Repot in fresh, airy mix, using a clean pot just large enough for the roots that remain. The pot must have drainage holes. If decay is widespread, save only healthy stem cuttings. Discard the plant if no healthy stems remain, and disinfect your tools afterwards.
• New speckling (stippling) with fine webbing: The leaves naturally have silver markings. Inspect damaged leaf undersides with magnification; tapping a leaf over white paper can help locate mites. Confirm spider mites before treatment. Isolate the plant, gently rinse both leaf surfaces and let water drain. Recheck every few days and repeat rinsing while live mites remain.

Name meaning of Hoya flagellata

Hoya honours the English gardener Thomas Hoy. The epithet flagellata means whip-like.