Hoyas are native to Indo-China, Indonesia and Australasia, and in this country they need to be grown in a warm bright room in the house or heated conservatory. The most commonly grown are Hoya carnosa and Hoya lanceolata ssp. bella (syn. H. bella).
Spring and summer
- Place in a sunny, light position, but shade from direct bright sun to avoid foliage scorch
- Water regularly and feed with half-strength high potash fertiliser every two weeks or so
Autumn and winter
- Make sure plants receive bright light
- Plants are relatively dormant and need only moderate watering from October to February. Water when the soil is fairly dry, but not dust dry
- Feeding can be reduced to once a month until growth resumes in spring
- In winter a minimum night temperature of not less than 10°C (50°F) for H. carnosa and 16°C -18°C (60-65°F) for H. bella
Do not move plants once flower buds form and do not remove the flower stalk (peduncle) after flowering as more flowers are often borne on the stumps of previous clusters.
Plants require a humid atmosphere – maintain good levels of humidity by standing the container on tray of gravel, expanded clay granules (Hydroleca) or recycled lightweight aggregate (Hortag) and keep moist, with the water level slightly below the surface of the gravel.
Re-pot in spring if needed, and do not feed for 5-6 weeks after re-potting.
Sharply draining, well aerated compost is essential for hoya to thrive. This can be made using one part by volume orchid bark, one part peat free compost and one part coarse perlite. Alternatively, use cactus compost but add some extra perlite.