Hoya is part of the Asclepiadaceae family. They can be found growing wild in South East Asia, including the East coast of Australia, Polynesia, and India. There are estimated to be 200-300 known species.
The delicate flowers of the Hoya are unusual and look as if they are made of wax, hence their common name of the wax flower. Many Hoya flowers are scented and can be found in shades of white, pink, red, yellow and burgundy. They thrive inside and can even be grown outdoors in warm, temperate gardens. With a bit of knowledge, they are easy to grow.
Hoya plants can be bought at garden centers, specialist plant stores, garden clubs or online. It is also possible to get cuttings of Hoya plants from friends and neighbors. Much of the author’s collection came from asking the local council for cuttings of plants from their hot houses.
The most common Hoya to buy and the easiest to grow is Hoya Carnosa which has round umbels of delicate pink flowers. There is a huge variety of Hoya, ranging from tiny leaved Hoya, such as Hoya Cummingiana to the huge leafed Hoya Loyceandrewsiana, with leaves as big as a small lunch plate.
Most Hoya is of a twining nature and are suited to hanging baskets. A few Hoya grow in a lax, upright manner.
When selecting a young plant be sure it has healthy leaves with no sign of scale, which can be seen as brown, yellow or white patches on the undersides of the leaves. Plants with leaves that are going brown and look as if they are rotting have probably been over watered and the damage is already too far to remedy.
Hoya are epihytic, growing on trees and in crevices in tropical regions. They like to have plenty of air circulation around their roots and do not like to be water logged at all. A common mistake when growing Hoya plants is to keep the soil consistently moist as with many tropical plants. Instead, let the soil dry out completely between watering, once a fortnight should be enough. Orchid mix is an ideal potting mix for Hoya as it is free draining and will not become water logged.
The flowers should not be picked as they bloom on the same spur each year. Picking the flowers will reduce spurs for future flowering.
Hoya enjoys warm conditions with temperatures of 60-75 degrees F (16 – 24 degrees C) but many can tolerate temperatures as low as 0 degrees Celcius.
They require bright light but not direct sunlight as this will burn the leaves.
Hoya plants like to be pot bound so only need repotting about every two years, depending on growth. When potting up it is important to put the plant in a pot only one size larger. Do not pot up when the plant is in flower.
Cuttings of Hoya are best taken from stems with at least two leaf nodes but cuttings can also be taken from just one leaf placed in the soil. These leaf cuttings can take several years to produce a new shoot but are an alternative option when a stem cutting is not possible.
The delicate, waxy flowers of the Hoya give a tropical look to any home or temperate garden. With a little knowledge and patience, the home gardener can propagate, grow and care for these beautiful plants. Hoya needs warm shade, crowded roots, and water, only after the soil has dried out, making them the ideal plant for the time-challenged gardener.