CULTURAL NOTES FOR HOYAS
Hoyas can be grown from seed or by cuttings. The easiest and quickest method is the latter. Cut lengths of the vine (or branch) with 2 or 3 nodes just below the leaf node. Remove the leaves at the base of the cutting, use root hormone if desired, insert into moist starter mix (3 parts of perlite and 1 part of peat). Cuttings can be left in water until roots appear, this takes approximately 3 weeks.
Hoyas seeds are contained in a bean like pod which will stay on the plant for almost 12 months and when mature will burst open and the seeds ‘float’ away to find a suitable place to grow. Seeds must be sown while fresh and will germinate in a couple of days.
When the Hoya cuttings are established they can be potted on into a well drained mix similar to an orchid mix.
Water and Light
Keep Hoya plants damp but do not overwater, they do not like wet feet. Cut back on watering during winter months.
Hoyas prefer early morning sun and need to grow in bright light to ensure blooms. They grow well when hung under trees where they get filtered light.
Fertilize with Osmocote® or half strength fertilizer such as Miracle-Gro® or Phostrogen in spring, summer and autumn.
Plants can be pruned to shape and size when necessary.
Hoyas can be susceptible to mealy bug, scale and aphids. Use Confidor® for mealy bug. The treatment should be repeated a few times at fortnightly intervals. Use Pest Oil for scale or sooty black mould. Aphids can be crushed by hand or sprayed with a water based fly spray.
Cool growing Hoyas will tolerate temperatures down to 2 deg C, intermediate species will tolerate down to 10 deg C, while warm growing species require minimum temperature of 15 deg C.
Listed here are some cool growing Hoyas which we grow in our garden in Sydney.
Hoya arnottiana - a species from India, has large umbels of white flowers.
Hoya australis - grows in Australia from Kempsey through to North Queensland, flowers are perfumed, white with a touch of red around the corona
Hoya bella (basket type). This species is from North India and grows in the crevices of trees and cascades. The flowers umbels form a cluster of approximately 7 flowers which have white petals with pink coronas. This Hoya flowers readily and makes a lovely show in a hanging basket, it can have three flushes of flowers in the warmer weather.
Hoya carnosa - from China, is very widely grown in Australia. We have it growing about 5 metres up a large tree, it gives a stunning display three times a year with its cascading pale pink flowers.
Hoya carnosa ‘Krimson Queen’ – cultivar with variegated leaves, pink flower.
Hoya cinnamomifolia - from Java is spectacular with green/yellow flowers with purple corona.
Hoya compacta ‘Indian Rope’ - flowers similar to H. Carnosa, a slow grower, best in a basket.
Hoya cumingiana (basket type) - from Philippines is a non twining plant with perfumed yellow flowers.
Hoya fungii - from Vietnam, large umbels of white flowers – flowers readily.
Hoya globulosa - a strong climber with large veined leaves, yellow flowers.
Hoya ‘Green Exotic’ – cultivar, dark pink flower, flowers readily.
Hoya 'Jungle Garden' – cultivar, dark pink flower, flowers well.
Hoya kerrii - from Thailand has a heart shaped leaf, handles dry conditions.
Hoya lanceolata (basket type) - from India, similar to H.bella.
Hoya linearis (basket type) - from India, think pencil leaves, white flowers.
Hoya longifolia (basket type) - from India, perfumed white furry flowers, flowers readily.
Hoya ‘Minibelle’ – cultivar, pale pink flowers. Flowers readily.
Hoya motoskei - from Japan, white flowers with red corona. Flowers readily.
Hoya obovata - has circular leaves, reflexed white flower with red corona, flowers readily.
Hoya pauciflora - from India, lanceolate leaves, single white flowers.
Hoya pubicalyx ‘Pink Silver’ – cultivar, dark pink flowers with silver/white edge.
Hoya pubicalyx ‘Red Buttons’ - cultivar. This Hoya has very dark red/black flowers and is very popular.
Hoya pubicalyx ‘Royal Hawaiian Purple’ – cultivar, dark purple flower.
Hoya polyneura (basket type) - from India, has fishtail type leaves, cream flowers with a red corona.
Hoya potsii - from Australia and New Guinea. These flowers vary in colour from cream through to yellow depending where they come from.
Hoya serpens (basket type) - This Hoya grows in the shade and has small round leaves and pale green flowers.
Hoya ‘Shepherdell’ – cultivar, pale pink flowers.
Hoya shepherdii (basket type) - has pale pink flowers, flowers readily.
These Hoyas can be grown either in a basket and cascade or on a trellis or similar type of support. The “basket type” Hoyas are non-twining and all grow well in hanging baskets where you can admire the flowers from beneath.
Hoyas flower from October through March, some producing two or three flushes during the season giving a continuing show of Hoyas. Some of my favourite Hoyas are H. bella, H. ‘Minibelle’, H. fungii and H. ‘Red Buttons’, these Hoyas flower well and really are most rewarding. Hoya flowers come in such an array of colours and colour combinations they are all beautiful. Hoya pauciflora lives up to its name “poor flowerer”, but when it does flower it is stunning with its large single cup shaped white flowers.