Hoya caudata (Hoya flagellata)

Identity and natural origin of Hoya caudata (Hoya flagellata)

Hoya caudata, also sold under the older name Hoya flagellata, comes from southern Thailand and western Malesia, including Borneo, the Malay Peninsula and Sumatra, where it climbs on trees in wet tropical habitat.

What Hoya caudata needs to grow well

The vines can climb a trellis or hoop, or trail from a container. Give bright indirect light and about 16–24 °C, with 50–60% humidity and gentle airflow. Shelter the leaves from hot sun and keep temperatures above about 10 °C.

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.

Use a light balanced orchid feed about every two weeks during new growth. Increase pot size only for crowded roots. Replace poorly draining mix in a pot sized to the roots.

Take a healthy one- or two-node stem cutting with a clean blade and wear gloves to avoid contact with the milky sap, which can irritate skin in some people. Remove the lower leaves. Root the cutting in a lightly moist, airy mix, keeping the remaining leaves above it. Keep it warm in bright indirect light and humid air with ventilation while roots form. Pot into airy mix once a healthy root system has developed.

What to check when Hoya caudata is struggling

• 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.