Hoyas look delicate and are not. Clemson Extension describes them as resilient plants that tolerate less-than-ideal conditions. Most trouble comes from two directions: a pot that stays wet, which rots the roots, and too little light, which stops flowering. A third is human: cutting off the old flower spurs that would have bloomed again.

This guide covers Hoya carnosa, the wax plant or honey plant, and the other common hoyas sold as houseplants. NC State Extension says the genus holds over 550 species of climbing epiphytes from tropical Asia, the Pacific islands and northern Australia. They belong to the dogbane family (Apocynaceae). For the species and cultivars you are likely to meet, see our hoya varieties guide.

Hoya care at a glance

FactorWhat the sources say
LightBright indirect light year-round (NC State). Medium light to grow, high light to flower (Missouri)
WaterLet the mix dry between waterings (NC State, Clemson). Moderate in winter (RHS)
MixLoose, fast-draining, organic mix (NC State). Equal parts potting soil, orchid bark and perlite (Clemson)
Temperature16–24 °C (61–75 °F) in spring and summer; minimum 10 °C (50 °F) at night for H. carnosa (RHS)
HumidityLoves high humidity (NC State); raise it with a tray of damp gravel (RHS)
FeedingEvery couple of weeks in spring and summer; monthly in autumn and winter (RHS)
RepottingOnly when it outgrows the pot; it tolerates being pot-bound (NC State)
PropagationStem cuttings or layering (NC State, RHS)
PetsNon-toxic to dogs and cats (ASPCA)

Light: enough to grow, more to flower

NC State says bright indirect light year-round is ideal for Hoya carnosa. For the genus, it notes most species need bright light, dappled shade or full morning sun, but not full sun all day.

University of Missouri Extension puts it in stages: hoyas tolerate low light, need medium light to grow, and need high light to flower. Clemson recommends a spot close to a west, east or south window. Near a south window, acclimate the plant to direct sun first to avoid leaf burn. The RHS warns that hot summer sun can scorch the leaves.

In a dim home, Clemson suggests an LED grow light. It also notes that low light can hold back both flowering and strong variegation.

Watering: let it dry, but read the leaves

Hoyas are epiphytes. In the wild they grow on branches, and the RHS notes their semi-succulent leaves store water. NC State says to let the soil dry out between waterings, and warns that soil kept too wet or too dry can make the leaves drop.

The sources differ on how dry:

  • Clemson says to let the mix dry out completely between waterings. It recommends the weight test: learn how light the pot feels when dry.
  • The RHS says to water regularly from spring to autumn, keeping the compost moist but never waterlogged. From October to February, wait until it is fairly dry, but never completely dry.

We read these together: water thoroughly, let it drain, and wait until most of the mix has dried. In winter, wait longer. The RHS warns that damp conditions in winter can rot the roots and kill the plant.

Leaves are a useful gauge. Firm, plump leaves are fine. Soft, wrinkled leaves mean the plant is short of water, from dry mix or from damaged roots. Our hoya wrinkled leaves guide explains how to tell which.

Mix, pot and repotting

NC State recommends a loose, fast-draining potting mix high in organic matter, in a container with good drainage. Clemson’s blend is one part potting soil, one part orchid bark and one part perlite. The RHS suggests equal parts orchid bark, peat-free multi-purpose compost and coarse perlite, or cactus compost with added perlite.

Repot rarely. NC State says the wax plant does not mind being pot-bound, and should be repotted only when it outgrows its container and is not in bud or flower. The new pot should be no more than 5 cm (2 in) larger. The RHS recommends spring for repotting. Clemson warns that a pot too large for the root ball keeps the mix wet and can cause root rot.

Humidity and temperature

NC State says the wax plant loves high humidity. It suggests a humidifier or a tray of wet pebbles. The RHS recommends standing the pot on damp gravel or clay pellets, with the water level just below the surface so the compost does not soak it up.

The RHS gives a range of 16–24 °C (61–75 °F) in spring and summer. Hoyas go semi-dormant in winter and should be kept cooler and drier. The RHS minimum night temperature is 10 °C (50 °F) for H. carnosa; H. bella needs warmer nights. Keep plants away from radiators and cold draughts (RHS).

A summer outdoors helps, according to Clemson, in a shaded spot once temperatures stay above 16 °C (60 °F). NC State says to bring it back inside when nights fall below 10 °C (50 °F).

Feeding

The RHS says hoyas need only light feeding. In spring and summer, feed every couple of weeks; a balanced orchid feed, preferably free from urea, works well. Cut back to once a month in autumn and winter. Flush pots with plain water every few months to prevent salt build-up, and wait five to six weeks after repotting before feeding.

Clemson suggests a liquid fertilizer with an N-P-K ratio of 2:1:2 or 3:1:2 to support flowering. It prefers liquid over slow-release granules because hoyas are watered infrequently.

Flowering: leave the spurs alone

NC State says most plants do not flower until they are 2 or 3 years old, and may bloom in spring, summer or autumn. Flowers form on short stalks called peduncles, or spurs. These rebloom for several years, so cutting them off removes future flowers. The RHS agrees: do not deadhead.

Buds are sensitive to change. The RHS says hoyas may drop their buds if the compost is too dry or too wet, or if light levels change. Missouri Extension says plants should not be moved. Once you see buds, keep care steady and leave the plant where it is. Our hoya blooming guide covers the checks in order.

Pruning and training

Hoyas climb or trail. NC State and Clemson recommend a trellis, hoop or pole for climbing, or a hanging basket for trailing. NC State says prune in early spring, before rapid growth begins. The RHS suggests light pruning in late winter or early spring, cutting just above a side shoot or leaf. Hoyas do not respond well to hard pruning.

Wear gloves. The RHS notes the milky sap can irritate skin.

Propagation

NC State lists stem cuttings as the recommended method, and Illinois Extension adds leaf-bud cuttings. The RHS describes two methods for spring or early summer:

  1. Semi-ripe cuttings. Take cuttings from the previous year’s stems. The RHS says they root in water in two or three weeks; then pot them into cuttings compost.
  2. Layering. Peg a low shoot into a pot of compost, keep it moist until it roots, then cut it from the parent.

Problems and what to check

What you seeLikely causeWritten guide
Soft, wrinkled leavesDry mix, or roots damaged by wet mixHoya wrinkled leaves
Yellow leavesMost often wet, poorly drained mix; also dryness, sun, cold or variegationHoya yellow leaves
Healthy plant, no flowersToo little light, young plant or cut spurs (NC State, RHS)Hoya not blooming
Tiny white flying insectsWhiteflies (RHS)Whiteflies on hoya
Cottony tufts at leaf jointsMealybugs (Clemson, RHS)Dab with a cotton swab dipped in isopropyl alcohol, or use insecticidal soap (Clemson)
Fine webbing, speckled leaves in winterSpider mites in dry heated air (Clemson)See our spider mite guide
Dropping or blackening leaves, diebackWaterlogged mix, or too cold in winter (RHS)Check roots and position
Wilting with damp mixOverwatering or overfeeding (RHS)Check roots; flush salts; feed less

The RHS says a hoya with root rot will not usually recover, so take cuttings from healthy stems as soon as you notice it. Our root rot guide covers the checks.

Are hoyas safe for pets?

The ASPCA lists wax plant, Hoya carnosa ‘Krinkle Kurl’, as non-toxic to dogs and cats. The RHS notes that the sap can irritate skin. See our pet-safe plants guide and the hoya hub for more.

References