Hoya : Greenhouse Plants
W – warm, minimum of 13°C (55°F)
These are lovely evergreenwith attractive shiny thick leaves. The flowers are waxy and curious in shape and they are frequently referred to as Wax Flowers. There was nothing better than going into the greenhouse at Wisley first thing in the morning and tasting the drop of nectar hanging on the tip of each flower that hung over our heads in the warm corridor. Growing them is extremely easy. They tend to be shallow rooted, especially while establishing, so a light peat-based is preferable. The surface of this should be allowed to dry out between waterings. They do not like too hot a temperature and a minimum of 10°C (50°F) during winter is ideal. Most commonly grown is Hoya carnosa from Queensland and its varieties which include variegated and coloured leaves. H. bella from Burma and Indonesia is a smaller plant which likes to trail rather than climb; ideal for hanging baskets. H. multiflora from Malacca is a very upright plant with yellowish flowers and very recurved petals. You will have to search hard to find sources of other species of which there are many. H. purpureo-fusca from Java seems to turn up occasionally. Even when not in flower it is easily recognised by the silver blotches on the leaves. Flowers are a maroon-pink colour and I have seen it referred to as Hoya ‘Silver Pink’. Propagation is straightforward by in spring. Seed is often produced in long thin pods and can be sown at a temperature of 24°C (75°F). Plants usually flower freely under glass but failure may be due to over feeding; they like to be a little potbound and in good light. Remember never to cut off old flower stalks as more flowers will be produced from them.