Hoya problems
Most of what goes wrong with a hoya comes down to a small number of causes, and they produce overlapping symptoms. This is what actually goes wrong with this plant, what separates one cause from another, and where to go for a specific symptom.
What is specific to this plant
- Hoyas are epiphytes with thick waxy leaves that store water, so they want to dry out far more than their leafy neighbours do.
- Do not cut off the bare stalk a flower cluster came from. Hoyas rebloom from the same spur for years, and removing it costs you next year's flowers.
- Long bare vine with no leaves is normal growth reaching for support, not a symptom.
What it could be, and how to tell
These look alike in a photograph, so each one below lists what you would ALSO see if that is the cause. Work down the list and stop at the one where the other symptoms match too.
1. Overwatering, and the root rot that follows
What else you would see
- yellowing that starts on the lowest, oldest leaves and works upward
- stems soft or dark at the soil line, sometimes with a sour smell
- soil or mix still wet several days after watering, when this much should have dried: most of the pot
- small flies around the pot, which breed only in constantly wet soil
What to do
- Stop watering and let it dry down this far: most of the pot.
- Check that the pot drains and empty any saucer or decorative outer pot it sits in. Water held out of sight keeps the mix wet whatever you change above it, and it stays invisible until you lift the pot.
- If the roots are soft and brown, trim them back to firm tissue with a blade sterilised first and repot into fresh chunky, very free-draining mix.
2. Not enough light
What else you would see
- long bare stretches of stem between the leaves
- each new leaf smaller than the last
- lower leaves shed while the growing tip carries on
What to do
- Move it to bright indirect light, with some direct sun tolerated.
- Cut back the stretched growth. It will not compact again on its own, and cutting back is what triggers branching.
- Turn the pot every couple of weeks so it grows evenly.
3. The flower spur cut off after blooming
What else you would see
- healthy growth and good leaves, but no flowers in a plant old enough to bloom
- a tidy plant with every bare stalk trimmed away
- flowering that happened once and never repeated
What to do
- Leave every bare stalk on the plant, however untidy it looks.
- Give it the brightest light it will take, since flowering is light-driven on this plant.
- Be patient with a plant whose spurs are gone, as it has to build new ones before it can flower again.
4. Underwatering
What else you would see
- leaf edges dry, thin or crisp rather than limp
- soil shrunk away from the side of the pot, and a pot that is light to lift
- the whole plant flagging at once rather than one leaf at a time
What to do
- Water thoroughly until it runs freely from the drainage holes, rather than a splash at the surface.
- If the mix has gone water-repellent and the water runs straight through, stand the pot in a basin of water for half an hour to rewet it properly.
- Water on dryness rather than on a fixed day of the week, and this is how far it should dry: most of the pot.
5. Spider mites
What else you would see
- fine pale stippling or speckling across the leaf rather than solid patches
- very fine webbing where the leaf meets the stem
- a dusty look to the underside of the leaf, worst in warm dry air
What to do
- Isolate the plant from your others straight away, before anything else.
- Rinse the leaves thoroughly, undersides included, with a strong spray of water, and repeat every few days. Mites breed faster than a single treatment can keep up with.
- Raise the humidity around the plant. Mites thrive in warm dry air and struggle in humid air.
- If you choose to use a treatment product, follow the label on it exactly. The label is the legal instruction and it overrides anything written here.
6. Rootbound, or soil that is worn out
What else you would see
- roots circling the inside of the pot or escaping the drainage holes
- water running straight through with almost no absorption
- two or more years in the same pot, and smaller new growth each season
What to do
- Repot one size up in spring into fresh chunky, very free-draining mix, teasing the outer roots loose.
- Feed during the growing season, following the instructions on the label of whatever you buy.
Common questions
What is the most common problem with a hoya?
Too much water, by a distance, and it is common because it looks like thirst: roots that have rotted cannot drink, so the plant wilts while standing in wet mix. Hoya wants this much to dry between waterings: most of the pot.
How much light does a hoya need?
Hoya wants bright indirect light, with some direct sun tolerated. Light problems show up in the growth rather than the colour: smaller new leaves, longer gaps between them, and lower leaves shed to fund the tip.
Why does my hoya look worse after I repotted it?
Some drooping in the week after a repot is ordinary shock and passes. Getting steadily worse over several weeks usually means the new pot is much too large, so the mix nothing is drinking from stays wet, or that the mix itself holds too much water.
Before you act on any of this
This is general plant care guidance for a plant, not advice about people or animals. We never tell you whether a plant is safe to eat or touch, and we never tell you a plant is safe for a child or a pet. If a child or animal may have eaten any part of a plant, contact Poison Control (US 1-800-222-1222) or a vet immediately rather than reading further.
Treatment advice here is deliberately category level. We do not give product names, mixing ratios or application intervals. Whatever the label on the product in your hand says is the instruction that counts, and following it is your responsibility.
Where this comes from
The general horticultural facts behind this differential come from published university extension and Royal Horticultural Society guidance. What is specific to this plant, and the order the causes are ranked in, is ours, and the methodology page says where that reasoning stops being reliable.
- Indoor Plants: WateringClemson Cooperative Extension Home and Garden Information Center
- Common Houseplant Insects and Related PestsClemson Cooperative Extension Home and Garden Information Center
- Root Rots on HouseplantsUniversity of Wisconsin-Madison Division of Extension
- Low Light Impacts on Indoor PlantsUniversity of Maryland Extension
- Glasshouse red spider miteRoyal Horticultural Society
Other hoya problems
Not sure which one it is?
PlantRx is an iPhone app that reads the photo and gives you the same kind of ranked differential you just read, for your plant specifically, with the evidence it based each answer on. The first diagnosis is free, in full. There is no subscription and no account.