Hoya Care guide

Hoya

Family: Asclepiadaceae
Latin name: Hoya

Numerous varieties with each one having unique colors and shapes! Their beauty is not only focused on their flowering but also on their foliage.

They are popular houseplants that can bloom from the first year.

Also known as 'wax plants' and 'porcelain flowers'.

It is often difficult to distinguish one variety from another and this distinction is usually made by their flowers. With experience one can also distinguish differences in leaf morphology.

Classification:

Hoyas belong to the family Apocynaceae. The first Hoya was classified in its genus in 1810. As of 2015 there are more than 500 Latin names published and new species are constantly being discovered and classified. According to botanists and experts in the genus, there are 600-700 species of Hoya, with many of them yet to be described and named. However, it is not one of the easiest plants to collect, as many of them grow epiphytically in the treetops. 

Most varieties are found in subtropical and tropical Asia, especially in the Philippines, Indonesia, Malaysia and Papua Guinea. They can also be found in Thailand, China, Singapore, Singapore, India, Colombia, Japan and Australia.

Most varieties are found at altitudes below 1000m, but a few others can be found very close to sea level. The varieties found at high altitude (such as Hoya linearis) need more knowledge to survive indoors, as they usually require lower temperatures at night and frequent water spraying.

Requirements:

• Substrate: They need soil rich in nutrients, with good aeration and drainage. Repotting should not be frequent as the plant likes to be 'cramped' in its pot due to its epiphytic nature. A mixture of 1/3 peat, 1/3 perlite and 1/3 pine bark is satisfactory for most Hoyas.
• Fertilization: Like all plants, they need regular fertilization during their growing season with a liquid or granular fertilizer. Fertilization should be discontinued in the winter months with cold temperatures.
• Watering: During the growing season they need regular watering, but after their soil has dried out. In the winter months watering should be significantly reduced.
• Lighting: Very important for Hoyas as insufficient light does not lead to proper flowering. Direct sun exposure should be avoided as it can cause burns on the leaves.
• Temperature: As tropical plants being tropical, low temperatures should be avoided. An ordinary room temperature is ideal.
  
  

Propagation:

Usually done with cuttings at least 10cm long, taken from the plant in early spring. This allows the new plant to take root during the growing season. The graft can be placed in water until it takes root or in soil which should remain moist until new growth appears.

Pests and diseases:

Aphids, tetrapods and ants can attack Hoyas as they are attracted to their sweet and fragrant nectar. Control can be done either naturally (water pressure, spraying with a dilute mixture of water and soap), or with a suitable insecticide.

Hoyas are generally very easy plants to grow indoors. With proper care you can have a tropical plant in your home!

Problems:

• Leaves browning/ turning red - the plant is in direct sun exposure. It should be moved to another location.
• Leaves are shrinking - the plant is not getting the water it needs (or moisture), there may be root necrosis or pseudocorm infestation.
• The plant looks weak and stunted - the roots may have been damaged either by overwatering or lack of water. Check the roots and if this is the problem, cut a healthy graft for propagation.
• The stem spaces between the leaves are too long - The plant is looking for light as in its location the light is not sufficient. Place it in a brighter spot.
• The plant does not flower - lack of sufficient light. Some varieties of Hoya, however, require some kind of 'stress' to promote flowering (e.g. low temperature or a period without watering). This is usually determined by the type of Hoya and the ecosystem in which it grows in the wild.
• Buds fall off before they open - the substrate has been left dry for a long time or too wet for a long time.
• Leaves fall off abruptly - usually means the plant suddenly received very cold temperatures.
• Leaves are sticky - If the plant is not in flower, it probably has an insect infestation. Check for insects on the leaves and act accordingly.