How to Grow Hoya (Wax Plant) and Get It to Flower Again

The single most useful thing to know about how to grow hoya is this: never cut off the little leafless stubs where the flowers were. Those spurs flower again, year after year, and snipping them “to tidy up” is why so many wax plants never bloom twice. The rest is simple: bright light, a snug pot, and watering only after the mix dries.

Why won’t my hoya flower?

This is the question most owners really have, so it comes first. Three things decide blooming.

Age. NC State Extension notes most plants do not flower until they are two or three years old. A small rooted cutting from a nursery needs time.

Light. A hoya in a dim corner grows leaves forever and never flowers. It needs bright light, ideally with a little gentle direct sun.

The spurs. Flowers grow from short woody stalks called peduncles. After the flowers drop, the stalk stays. Leave it. The plant reuses the same spur for new clusters for several years. Also leave long bare runner stems alone for a while; leaves follow along them later.

Which window suits hoya in a Pakistani flat?

East is best: morning sun until mid morning, then bright light all day. A south window is excellent from October to March, when the low sun is gentle; from April, hang a thin curtain or move it a metre back, because a Lahore or Multan noon sun through glass yellows the leaves. West glass in summer is too hot. North light keeps it healthy but it may never flower there.

A gentle blush of red or pink on the leaves in bright light is normal sun colouring, not a disease.

By zone: Karachi’s humidity suits hoya so well it can grow outdoors on a shaded balcony all year. In Multan, Sukkur and Bahawalpur keep it indoors away from the cooler blast in summer, since dry hot air and spider mites go together. In Lahore, Faisalabad and Delhi, a balcony works from March to November, but bring it in before nights fall toward 10°C, which NC State gives as the point to move it indoors. Islamabad, Peshawar and hill homes: an indoor plant for the cool months.

How often should you water hoya?

Thick leaves store water, so it prefers a drink after the mix dries rather than constant dampness. NC State notes that both very wet and very dry soil can make it drop leaves, so aim for the middle.

Slightly soft, bendy leaves mean it is thirsty. Yellow, mushy leaves with wet soil mean too much. Our potted plant watering guide has the finger test.

What is the best soil for hoya?

In nature many hoyas climb trees, rooting in bark and leaf litter, so they want air at the roots. Use 1 part potting soil, 1 part cocopeat or leaf mould and 1 part perlite, with a handful of small bark pieces or brick chips. Ordinary heavy garden soil holds water and rots the roots. Our potting mix ratio guide explains how to make a mix airier.

Feed with a half strength balanced liquid feed once a month from March to September. Repot rarely: NC State advises moving up no more than 2 inches in pot size, and never while it is budding or in flower. Give it a small trellis, a hoop, or let it trail from a hanging pot.

How do you propagate hoya?

Stem cuttings root reliably in warm months.

1. Pick a healthy stem with leaves, not a bare runner, between March and September.
2. Cut a piece with at least two nodes (the joints where leaves grow), about 4 to 6 inches long.
3. Remove the leaves from the lowest node, which goes under the mix.
4. Let the cut dry for a few hours in shade. Hoya sap is milky; wipe it off your hands.
5. Root it in a jar of water, damp perlite, or a mix of cocopeat and perlite.
6. Keep it warm and bright but out of direct sun. Cover loosely with a clear plastic bag in dry weather to hold humidity.
7. Roots typically appear in a few weeks in summer. Pot water rooted cuttings once roots are an inch long.

Layering also works: pin a long stem node onto a small pot of damp mix beside the parent, and cut it free once it has rooted. Expect a new cutting to take a couple of years to flower.

Why are hoya leaves turning yellow?

• Yellow and soft, wet soil: overwatering. Let it dry, check that the hole drains, repot in airy mix if roots are brown and mushy.
• Yellow and wrinkled, dry soil: it went too dry for too long. Soak it, then return to a steady rhythm.
• Pale yellow, bleached patches: harsh direct sun through glass.
• Leaf drop in winter: cold window or cold water. Move it into the room.
• White fluff in leaf joints: mealybugs, hoya’s most common pest. See our organic steps for pot pests.
• Speckled, dull leaves with fine webs: spider mites in dry air. Wipe leaves and raise humidity.
• Fungus gnats: the mix stays too wet. Water less often.

Grow it or skip it?

Grow it if you have an east window or a bright curtained south window and you can be patient for two or three years before the first flowers. After that it is one of the most rewarding houseplants, flowering from the same spurs season after season. Skip it if you only have a dark north room and want flowers, or if you are a frequent repotter and pruner by nature. It is a pot plant in our region except on frost free Karachi balconies. More flowering plants are in our Phool aur Paudhe section.

Hoya (wax plant) questions answered

Sources

• NC State Extension Plant Toolbox: Hoya carnosa
• ASPCA Animal Poison Control: Wax Plant