It should be easy to pick a favourite from the Hoya family — after all, it has more than 200 distinct species and numerous colourful blooms, writes Stephanie Choo
THE beauty of the genus Hoya lies in its colourful ball-like blooms and outstanding foliage. This group of plants comes in a vast array of forms, hence making them attractive to home gardeners and plant collectors alike. In fact there are societies formed to learn, share and promote the cultivation of hoyas.
The Hoya is a genus of over 200 distinct species and numerous cultivars in the Apocynaceae, or dogbane, family. They are actually tropical plants found in Asia including China, India, Thailand, Malaysia, Indonesia, China, Philippines, Polynesia, New Guinea and Australia.
Most hoyas are epiphytic and some are entirely terrestrial, either in the more common vining type or bushy form, while the stalks are woody, soft and succulent or thin and wiry.
Their five-pointed star-shaped blooms are often scented, nectar- producing and grow in umbels, in different sizes, colours and textures, depending on the variety. The number of flowers in each umbel varies from one to numerous. The leaves, just as pleasing as the flowers, also come in diverse shapes, sizes, textures, variegation and venation. Some are papery and some fleshy.
NAMES AND VARIETIES
There are a number of vernacular names for the hoya such as the more popular wax plant, wax flower or wax vine as these names describe the appearance of the plant itself, while many just call them by the genus name, hoya.
Besides being known as a wax plant, the Hoya carnosa is also called Porcelain Flower, as it has clusters of sweet-scented, stiff, small and waxy or porcelain-textured star-shaped flowers in white and pink. One of its cultivars, Hoya carnosa ‘Compacta’, is called the Hindu Rope or Kinkle Kurls as the plant has curvy and curly shiny green leaves.
The Hoya multiflora is named Shooting Stars because of its white flowers with yellow petals sweep back, resembling shooting stars. The blooms release a strong fragrance and produce lots of nectar. Interestingly, this hoya grows upright like a shrub.
Often said to be the easier hoya species to grow, Hoya pubicalyx (also called Harlequin wax plant) is an interesting option as it has more impressive flowers and wonderful glossy, speckled long leaves. Depending on the cultivar, the colours of the flower, or corona, range from a combination of white and pink to red and black. The plant has little nectar and a mild but nice scent.
The Hoya kerrii, generally referred to as wax hearts or sweetheart hoya, has outstanding thick, heart-shaped leaves. The leaves can be all green or variegated. Their flowers are, however, less spectacular — small, in red and white and vaguely scented, and there’s a lot of nectar.
Slow-growing but will grow with ease if watered wisely and fed regularly. The plants have the potential of beautifying an unappealing spot when used as a living screen.
They are usually sold in hanging pots at the nurseries. You may re-pot it to a new container that is about the same size or slightly bigger than the original one. Use a well draining soil mix — equal parts of sand or burnt soil, crushed pebbles or perlite, and black soil. Otherwise, just continue to grow the hoya as it is in its original pot. The plant loves to be pot-bound and this, in fact, will speed up flowering.
Grow hoyas in bright shade. Too much direct sunlight may scorch its leaves. Propagating the hoya using its stem cuttings is the easiest as compared with using its leaves or seeds. Water sparingly, about once a week or when soil surface feels dry to the touch. Do not underwater nor overwater a rooting plant. Once a hoya has established (root-bound and putting out new growth or blooming) water it on alternate days or even daily and feed more frequently. Start by feeding once a month, then gradually increase the frequency to once a week. Always feed lightly. Use any balanced or organic fertiliser.
Most species are twining vines. Install trellis or train vines to the wires that are holding the hanging pot. Otherwise, allow the hoya to climb naturally up a big tree, a pergola or cover a fence to create a screen. For shrubby ones, prune to promote branching and upright form.
Watch out for new shoots and train them back to the provided support. Else, they may grow onto nearby plants or structure.
New flowers will form on old peduncles or spurs (flower stalks), so do not discard any old flower stalks.
Some hoyas are able to tolerate more (or less) light and warmth than others. When the vine of a Hoya diversifolia has matured and is growing steadily and is well watered, it can even be grown in full sunlight.
If you have a young plant or newly rooted cutting, it will take the plant one to two years or more to mature and bloom. In the meantime, wait patiently and take good care of the plant!