|Propagation:||From seeds, cutting, layering|
|Adult size:||over 1-2 m indoors|
|Watering:||Let the soil mostly dry between waterings|
|Fertilization:||Monthly during active growth|
|Soil:||Very well drained|
|Humidity:||High humidity preferred, low humidity tolerated|
|See more Hoya|
Wax plant, porcelainflower, waxvine
Hoya carnosa is a vining epiphytic plant in the dogbane family Apocynaceae. It has attractive waxy foliage and produces sweetly scented flowers. Native to Australia, India and parts of southern China, it makes an easy houseplant, ideally suited for pots or a hanging basket.
- 1 Name
- 2 Characteristics
- 3 Care
The genus Hoya was named after the botanist Thomas Hoy.
Carnosa from "carnose" or 'flesh' refers to succulent and thick leaves.
The inflorescence is made up of multiple flowers, hanging or more upright, grouped in an umbel. The flowers are often light pink, but may vary from near-white to dark pink. They are star-shaped, and are borne in clusters that look like they are made of wax. The flower's surface is covered in tiny hairs giving a fuzzy appearance. They are heavily scented and may produce excess nectar that drips from the flowers.
Like all species of Hoya, H. carnosa flowers from spurs. These appear from the axils of the leaves and stem; flowers may not be produced when the spurs first appear, but in time buds emerge from the tips. Each season new flowers are produced on these same spurs, so they should not be damaged or removed.
The plant flowers from spring to late summer, it can produce umbels of 10 to 50 small star-shaped flowers that mature gradually (2 to 3 weeks) on the same peduncle. The scent is strongest in the early evening.
H. carnosa has firm and succulent leaves. H. carnosa has been in cultivation for over 200 years and so there are many different cultivars with a variety of variegations and leaf shapes.
The H. carnosa 'Hindu Rope ' or H.carnosa 'Compacta ' cultivar has twisted leaves which hang downwards, forming a rope-like appearance. Due to the cupped leaves and compact growth this cultivar is particularly prone to mealybugs.
The H. carnosa 'Krinkle 8' cultivar gets its name from the eight distinctive depressions on each leaf.
H. carnosa 'Krimson Queen' has green leaves with white variegated margins. New growth often has a pink hue which fades to white as the leaf ages.
H. carnosa 'Tricolor' has creamy white leaves with green splashes and margins. New growth has a pink tint.
H. carnosa 'Splash' green leaves with silver speckling.
H. carnosa 'Wilbur Graves' dark green leaves with heavy silver splashing, some leaves can be almost entirely silver with only a few flecks of green. New growth has a pink tint.
H. carnosa wants bright, indirect light. It can tolerate some morning or evening light but avoid hot midday sun or the leaves will yellow and scorch.
Use a very well draining soil mix and re-pot at least every other year with a coarse, extremely well draining substrate (see hoya soil). Water thoroughly, allowing excess to drain. A waterlogged soil will lead to yellowing leaves, followed by root rot and death. Never allow the plant's roots to sit in standing water.
H. carnosa is not hardy and foliage will burn and die if exposed to frost. It can handle continual temperatures down to 10°C (50°F) and growth will suffer in temperatures continually above 25°C (77°F).
Yellowing leaves are a sign of too much water. Ensure the pot has good drainage and allow the surface of the soil to dry between watering. If the soil is staying too moist for too long, consider repotting into a mix which dries more quickly - see hoya soil.
Thin or wrinkling leaves
Thin leaves are a sign of stress in Hoya. Check the plant has good drainage and isn't sitting in water or compacted soil.
Wrinkled leaves may indicate the plant is thirsty and needs water. If the plant has wrinkled leaves and the soil is being kept moist it could mean the plant's roots are rotting. Gently remove the plant from its container and check that the roots are healthy.
Dropping new leaves
If your H. carnosa is actively growing but drops any new leaves before they have fully matured it is likely a sign of water stress. Did you recently soak the plant? Or have you been letting the Hoya dry out for too long in between waterings? Try adjusting your watering schedule to reduce the large swings in conditions for the plant.
Hoya that are actively growing or about to flower require more water than a Hoya that is sitting dormant.
Slow or no growth
Hoya can be temperamental plants. A change in environment may send the plant into a partial dormancy and growth will stop for weeks or months. Give the plant time to adjust to a change in its surroundings, especially if it has recently been brought home from the store or been moved from outside in, or visa versa.
Hoya, especially those with thicker leaves, can occasionally produce foliage that is misshapen. This is normally because of stress during the production of the leaf - maybe the plant was overwatered, the temperature was especially high or low or the plant was moved into a new environment. New growth on the plant should be the 'right' shape, assuming the conditions are more consistent in future.
Vines dying back
Many Hoya send out leafless vines to seek out spots of sunlight and branches to twine and climb. Given time and light, these vines will produce leaves. However sometimes the plant will decide the vine is not viable and it will die back - if you see the tip of the vine shrivel then it is safe to cut it off. Just make sure it isn't a peduncle or you will be removing a flowering point for the Hoya.
Hoya are commonly propagated from cuttings. The cuttings can be rooted in water, sphagnum moss or directly into soil. See hoya propagation for a detailed guide.