PlantParlourWax plant (Hoya carnosa) care
Vines & trailers · easy to keep
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Wax plant (Hoya carnosa) wants bright indirect light, with some direct morning sun for flowers. Water it every 10 days. Water thoroughly when the pot is nearly dry and the leaves have just started to feel less firm. Hoyas store water in their leaves and are far more tolerant of drought than of wet feet. Pot it in very free-draining — orchid bark, perlite and a little compost. A balanced feed at half strength every second or third watering in spring and summer, and repot every 2 years. Humidity: room humidity is fine; above 60% speeds growth. The ASPCA lists it as non-toxic to cats and dogs.
The wax plant: thick leathery leaves on woody vines, and — given enough light and enough patience — umbels of star-shaped flowers that smell of chocolate at night and drip nectar onto whatever is underneath. Hoyas flower from short spurs that they reuse year after year, so the one rule is never to cut off an old flower stalk.
Quick facts
- Water
- Water every 10 days. Water thoroughly when the pot is nearly dry and the leaves have just started to feel less firm. Hoyas store water in their leaves and are far more tolerant of drought than of wet feet.
- Light
- Bright indirect light, with some direct morning sun for flowers.
- Humidity
- Room humidity is fine; above 60% speeds growth.
- Soil
- Very free-draining — orchid bark, perlite and a little compost.
- Feeding
- A balanced feed at half strength every second or third watering in spring and summer.
- Repotting
- Repot every 2 years.
- Toxic to pets
- Non-toxic to cats and dogs, though the milky sap can irritate skin. The ASPCA lists Wax Plant (Hoya carnosa 'krinkle kurl') as non-toxic to cats and dogs (checked 26 October 2026).
- Difficulty
- Easy.
- Mature size
- Vines to 3 m.
- Native to
- East Asia and Australia.
Watering a Wax plant
Water every 10 days. Water thoroughly when the pot is nearly dry and the leaves have just started to feel less firm. Hoyas store water in their leaves and are far more tolerant of drought than of wet feet.
That cadence is the one PlantParlour sets for this species when you name it, and it is deliberately on the cautious side — a plant that asks a day early is safer than one that asks a day late. Log each watering and the reminder moves with the plant rather than with the calendar.
Light
Bright indirect light, and a couple of hours of direct morning sun if you want flowers. Hoyas grown in medium light stay alive and green for years without ever blooming.
Humidity and temperature
Room humidity is fine; above 60% speeds growth. Central heating in winter is what turns a comfortable room into a dry one, and it is the usual reason an established plant suddenly browns at the edges or picks up spider mites.
Soil and potting
Hoyas are epiphytes that root into bark and moss. A chunky mix of bark and perlite with a little compost is right; ordinary potting soil holds far too much water.
Feeding
A balanced feed at half strength every second or third watering in spring and summer. Stop feeding in autumn and start again when you see new growth in spring — feeding a plant that isn't growing just builds up salts in the pot.
Repotting
Repot every 2 years. Rarely. Hoyas flower best tightly potbound, and repotting a plant that is about to bloom usually costs you the flowers. Every three or four years is plenty.
Common problems
-
Never flowers
Not enough light, too much pot, or the flower spurs were cut off.
Fix: Move it brighter, stop repotting, and never cut the old flower stalks — hoyas bloom from the same short spurs year after year.
-
Wrinkled, dimpled leaves
Under-watering — or, confusingly, root rot, which stops the plant drinking.
Fix: Check the roots. Firm white roots mean water it; brown mushy roots mean repot and cut the damage away.
-
Yellow leaves dropping
Overwatering or cold.
Fix: Let it dry out further and keep it above 15 °C.
-
Sticky black film under the flowers
The flowers themselves drip nectar; it is not a pest.
Fix: Wipe it off. Put a saucer under a plant that is blooming heavily.
Propagation
Cuttings with two nodes and a leaf or two root in water, perlite or sphagnum over four to eight weeks.
A cutting taken in PlantParlour keeps its link to the plant it came from, so a propagation years later still traces back to the mother plant — which is the point if you ever sell or trade it.
Toxicity and safety
Non-toxic to cats and dogs, though the milky sap can irritate skin.
The ASPCA lists Wax Plant (Hoya carnosa 'krinkle kurl') as non-toxic to cats and dogs (checked 26 October 2026).
If your pet has eaten a plant, call your vet, the ASPCA Animal Poison Control Center on (888) 426-4435, or the Pet Poison Helpline on (855) 764-7661. Both are open around the clock and may charge a consultation fee. Take the plant or its label with you.
This is general information, not veterinary advice. We don't test plants: what we say about toxicity follows the ASPCA's published plant list as it stood on 26 October 2026, and that list can change. "Non-toxic" means not poisonous — a pet that eats enough of any plant can still vomit, and fertiliser, pesticide or leaf shine on a plant can harm it. It also only helps if the plant is what you think it is. It covers cats and dogs only; ask your vet about rabbits, birds, reptiles or anything else, and a doctor about children. Read our terms.
Every houseplant in the library the ASPCA lists as non-toxic to cats and dogs
Named cultivars and variegations
Hoya carnosa is sold under several cultivar names. Care is the same unless noted; variegated forms carry less chlorophyll, so they grow more slowly and want more light than the plain species.
| Cultivar | Also sold as | Water |
|---|---|---|
| 'Krimson Queen' | Hoya Tricolor, Krimson Queen | every 10 days |
| 'Krimson Princess' | Krimson Princess | every 10 days |
| 'Compacta' | Hindu rope hoya | every 10 days |
| 'Chelsea' | Hoya Chelsea | every 10 days |
Where the variegated forms are grown differently from the plain Hoya carnosa:
'Krimson Queen'
Cream-white leaf margins; new leaves come in flushed pink when the light is good.
Light: Bright indirect light with an hour or two of morning sun. The pink flush on new growth only comes in good light; in a dim spot new leaves come greener.
Watch for: New leaves coming in plain green. The stem is reverting: green tissue grows faster than the cream, and a stem that has made one plain leaf will usually go on making them. Give it more light, and cut the stem back to a node below the last leaf with good variegation; growth from that node carries the pattern on.
'Krimson Princess'
Yellow-cream centres with green margins (the reverse of Krimson Queen), and pink new growth in good light.
Light: Bright indirect light with an hour or two of morning sun. The pink flush on new growth only comes in good light; in a dim spot new leaves come greener.
Watch for: New leaves coming in plain green. The stem is reverting: green tissue grows faster than the cream, and a stem that has made one plain leaf will usually go on making them. Give it more light, and cut the stem back to a node below the last leaf with good variegation; growth from that node carries the pattern on.
Questions people ask
How do I get my hoya to flower?
Bright light including some direct morning sun, a pot it has filled, and time — a hoya usually needs to be two or three years old. Never cut off the old flower spurs: hoyas bloom from the same short stalks repeatedly, and removing them costs you every future flush from that point.
Should I cut off the long bare hoya vine?
No, if you can bear it. Those bare runners are searching for something to climb and will leaf up once they find it. Train it around a hoop or up a trellis instead of cutting.
How often should you water a Wax plant?
Water every 10 days as a starting point — that is the cadence PlantParlour sets for Hoya carnosa. Water thoroughly when the pot is nearly dry and the leaves have just started to feel less firm. Hoyas store water in their leaves and are far more tolerant of drought than of wet feet. Light, pot size and the time of year all move that number, so treat it as a reminder to go and check rather than a rule.
How much light does a Wax plant need?
Bright indirect light, and a couple of hours of direct morning sun if you want flowers. Hoyas grown in medium light stay alive and green for years without ever blooming.
Is Wax plant toxic to cats and dogs?
Non-toxic to cats and dogs, though the milky sap can irritate skin. The ASPCA lists Wax Plant (Hoya carnosa 'krinkle kurl') as non-toxic to cats and dogs (checked 26 October 2026). If a pet has eaten part of a plant, call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 straight away.
How do you propagate a Wax plant?
Cuttings with two nodes and a leaf or two root in water, perlite or sphagnum over four to eight weeks.
Related plants
- Hoya 'Publicalyx Splash'
- Hoya 'Australis Lisa'
- Hoya 'Mathilde'
- Hoya 'Sunrise'
- Hoya kerrii
- Hoya linearis
- Hoya obovata
- Hoya krohniana
Or browse every plant in the library.
Keep this plant's record
PlantParlour gives your Wax plant its own page: a photo timeline, reminders set to the cadences above, and every watering, feed, repot and problem written down. Trade or sell it and the whole history goes with it.
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