Wax plant (Hoya carnosa) care

Vines & trailers · easy to keep

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. Non-toxic to cats and dogs, though the milky sap can irritate skin.

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.
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.

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

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?