Wax Plant (Hoya Carnosa)
Hoya carnosa
The wax flower: thick waxy leaves, long vines, fragrant umbels. Tolerates neglect, flowers indoors. Very trendy.
The Hoya carnosa — the wax flower — is one of the most collected plants in the world. Its thick waxy leaves, long trailing vines and especially its umbels of fragrant star-shaped flowers make it an exceptional plant. Rare for an indoor plant: it flowers regularly, sometimes several times a year, with a sweet evening fragrance.
What you really need to know
Easy plant for those who follow two rules: bright indirect light + don’t cut the flower stalks after blooming (the Hoya re-flowers from the same spurs the next year). Tolerates neglect, prefers being slightly root-bound.
Light
Bright indirect light. A few hours of soft direct sun (morning/late afternoon) beneficial. Without enough light, the Hoya never flowers. Optimum: east- or west-facing window.
Watering
Every 10 to 14 days during growing season, spaced out in winter. Let the top 3 cm dry before watering. Waxy leaves store water: the Hoya tolerates underwatering but hates excess.
Humidity and temperature
Ideal between 40-70 % humidity. Tolerates dry indoor air. Temperature 16-27 °C, never below 13 °C.
Flowering: the golden rule
Never cut the flower stalks after the flowers fall. These stems (called “spurs”) rebloom every year at the same spot. Cutting the spur = losing future flowerings.
Conditions to encourage flowering:
- Bright light (essential)
- Mature plant (3+ years)
- Slight dryness
- Slightly root-bound pot
Mistakes to avoid
- Cutting spurs: the biggest mistake, loss of future flowerings
- Pot too large: prefers being root-bound
- Overwatering: root rot
- Insufficient light: no flowering
Toxicity
✅ Non-toxic to cats and dogs. Ideal for pet households.
Propagation
Water cutting or directly in sphagnum. Cut a stem with 2-3 nodes and at least one leaf, let it root 4-8 weeks. Slower than other tropicals but works very well.
Popular cultivars
- Hoya carnosa classic: thick green leaves
- Hoya carnosa Tricolor (Krimson Queen): cream variegation
- Hoya kerrii: heart-shaped leaves (Valentine’s plant)
- Hoya pubicalyx: velvety silver-speckled leaves
Frequently asked questions
How often should I water this plant?
Water Wax Plant (Hoya Carnosa) every 10-14 days, adjusting for season, pot size and available light. Always check that the top of the substrate has started to dry before watering.
Is this plant toxic to cats and dogs?
Wax Plant (Hoya Carnosa) is classified as "non toxic". As a precaution, keep it away from pets that chew leaves and contact a vet if ingestion causes symptoms.
Why are its leaves turning yellow?
Yellow leaves on Wax Plant (Hoya Carnosa) most often come from overwatering, low light or recent stress. First check substrate moisture, root condition and placement.
Where should I place it at home?
Wax Plant (Hoya Carnosa) prefers bright indirect light. Place it near a bright window without harsh direct sun, then adjust if leaves fade, brown or growth slows.
Is it beginner-friendly?
Wax Plant (Hoya Carnosa) is a good beginner plant if watering stays moderate and regular.
Sources and method
This fact sheet is based on public botanical references, recognized horticultural recommendations and the SPRAIA editorial method.
- Royal Botanic Gardens, Kew
- Missouri Botanical Garden
- Royal Horticultural Society
- GBIF
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