Alocasia
Alocasia × amazonica
Dramatic arrow-shaped leaves with pale veins, and a plant that behaves seasonally indoors in a way most houseplants do not: it commonly drops most of its leaves in winter and regrows from the corm in spring. Owners routinely discard a dormant plant believing it dead.
- Position
- Bright, out of direct sun
- Water
- moderate demand
- Drainage
- Free-draining
- Grows to
- 45–100 cm × 40–80 cm
- Frost
- Frost tender
- Difficulty
- Demanding
Described view
A leafless alocasia pot beside a firm healthy corm lifted from it
August
Nothing to do
No sowing, planting, harvesting or pruning window falls in August.
Alocasia’s year
Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.
| Activity | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Take cuttings | April. | May. | ||||||||||
| Protect | January. | February. | November. | December. |
Timing that travels
The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.
Conditions it needs
- Light
- Partial shade, Dappled shade
- Frost
- Frost tender
- Grows best at
- 18–27 °C
- Soil
- Peat-free compost
- Soil pH
- 5.5–6.5
- Drainage
- Free-draining
- Water needs
- moderate
- Drought
- poor tolerance
- Waterlogging
- poor tolerance
- Heat
- moderate tolerance
- Wind and exposure
- poor tolerance
Where these figures come from
- LightSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — position
Checked 2026-08-13
- FrostSourced guidancehigh confidence
- Royal Horticultural Society: Alocasia — hardiness
Checked 2026-08-13
- Grows best atSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — temperature
Checked 2026-08-13
- SoilSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — soil
Checked 2026-08-13
- Soil pHSourced guidancemoderate confidence
- Plant Finder — Missouri Botanical Garden: Alocasia — culture
Checked 2026-08-13
- DrainageSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — soil
Checked 2026-08-13
- Water needsHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- DroughtHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- WaterloggingHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- HeatHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Wind and exposureHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
On your soil
Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.
| Soil | Verdict | Why |
|---|---|---|
| Heavy clay | Works, with one condition | Alocasia will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse. |
| Sandy | Works, with one condition | Alocasia will crop on sandy, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Chalky and alkaline | Struggles here | Alocasia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Loam | Grows well here | Alocasia grows perfectly well on loam without special measures, though it is not the soil it would choose. |
| Silty | Grows well here | Alocasia grows perfectly well on silty without special measures, though it is not the soil it would choose. |
| Peaty and acid | Works, with one condition | Alocasia will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse. |
| Shallow over rock | Works, with one condition | Alocasia will crop on shallow over rock, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Made ground and urban soil | Struggles here | Alocasia struggles on made ground and urban soil: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.2 to 7.8. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy. A container or a raised bed of imported soil sidesteps the problem entirely. |
Not sure which you have? Four hand tests will settle it.
Space and spacing
- Mature height
- 45–100 cm
- Mature spread
- 40–80 cm
- Rooting depth
- 20 cm
Where these figures come from
- Mature heightHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Mature spreadHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Rooting depthHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
In a container
- Minimum volume
- 3 litres or more
- Minimum depth
- 18 cm
Where the container figures come from
- Minimum volumeHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Minimum depthHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
Where and how you can grow it
Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.
| Method | Suitability | What it needs |
|---|---|---|
| Container | Well suitedsourceSourced guidancemoderate confidence
Checked 2026-08-13 | Indoors, or outdoors in summer only |
| Greenhouse | Well suitedsourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Indoor pot | WorkablesourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Windowsill | Not suitablesourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Open ground | Not suitablesourceSourced guidancemoderate confidence
Checked 2026-08-13 | Tender: will not survive a British winter outdoors. |
Growing it
- ProtectionCheck the leaf undersides for red spider mite through winter. Dry centrally heated air suits the mite far better than it suits the plant, and fine webbing between leaf and stem is the sign.
- Expect leaf loss in winter and do not respond by watering more. A plant that has dropped every leaf but has a firm corm is dormant, not dead, and will regrow in spring.
- WateringWater thoroughly in growth and let the top couple of centimetres dry between times, then change the regime deliberately in autumn — an alocasia slows hard as the light falls and many go fully dormant, dropping every leaf and leaving what looks like a dead pot of compost. It is not dead, and the single worst response is to keep watering it. A dormant tuber wants to be barely damp until spring, when it starts again. Yellowing leaves one after another through October is usually the beginning of that, not a problem to be fixed.
- FeedingFeed fortnightly at half strength while it is actively producing leaves in spring and summer — it is a hungry plant for its size and each new leaf is a substantial piece of growth. Stop entirely once growth slows in autumn and give nothing to a dormant plant. Alocasias are also sensitive to salt build-up, showing it as brown crisp leaf margins, so water the pot through with plain water occasionally to flush it.
- TransplantingRepot in spring as growth restarts, into a free-draining mix with plenty of bark or perlite, and only when the tuber has genuinely filled the pot — alocasias flower and grow better slightly restricted. Spring is also the moment to separate the offsets that form around the parent tuber. Never repot a dormant or leafless plant in autumn or winter: it cannot root into the new compost, and the compost stays saturated around a tuber that is trying to rest.
Where this guidance comes from
- ProtectionSourced guidancehigh confidence
- Royal Horticultural Society: Red spider mite
Checked 2026-08-13
- Item 2Sourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — dormancy
Checked 2026-08-13
- WateringSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — cultivation
Checked 2026-08-13
- FeedingSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — cultivation
Checked 2026-08-13
- TransplantingSourced guidancemoderate confidence
- Royal Horticultural Society: Alocasia — cultivation
Checked 2026-08-13
Safety and edibility
Listed as harmful to cats or dogs
Alocasia is listed as harmful if eaten. All parts carry needle-shaped insoluble calcium oxalate crystals, which drive into the soft tissue of the mouth on contact. The pain is immediate, which is why an animal rarely takes a second bite and why fatalities are rare — but the drooling and swelling that follow are real and distressing.source
Sourced guidancehigh confidence
- ASPCA Animal Poison Control Center — toxic and non-toxic plant list — American Society for the Prevention of Cruelty to Animals: Alocasia — toxic plants list
Checked 2026-08-13
Affected parts: all parts.
- Pets and livestockpetschildrenAll parts contain insoluble calcium oxalate crystals. Chewing causes immediate burning of the mouth, drooling and swelling — painful and distressing rather than usually life-threatening, and the pain generally stops an animal after one bite.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Alocasia — toxicity
Checked 2026-08-13
Keep alocasia out of reach of pets that chew plants and of small children. If chewed, rinse the mouth and offer water; seek veterinary or medical advice if swelling affects breathing or swallowing.
Sources for this page
GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society
Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-14.
If something is wrong with it
- Silvery or mottled leaf surface — 2 causes GrowingHQ holds for alocasia
- Lower leaves turning yellow — 2 causes GrowingHQ holds for alocasia
Something else? Work through it with the diagnostic tool.