Giant taro (Alocasia macrorrhizos) care

Aroids · straightforward to keep

Last updated 27 October 2026

Giant taro (Alocasia macrorrhizos) wants bright indirect light, as much as it can get without direct sun. Water it every 5 days. Water when the top third dries, and never leave the pot standing in a saucer of water. Alocasias also drip water from their leaf tips in the morning — that is guttation, and it means the roots are working, not that anything is wrong. Pot it in chunky and fast-draining: bark, perlite, a little coir. Balanced feed at half strength every second or third watering, spring through summer only, and repot once a year. Humidity: 60% and above, or spider mites will find it. Toxic to cats, dogs and people if chewed — the sap carries insoluble calcium oxalate crystals, which burn the mouth and throat.

Giant taro — the largest alocasia commonly grown indoors, with upright glossy leaves that can pass a metre in length on a mature plant. It is thirstier and hungrier than the smaller alocasias and needs both floor space and a bright spot to do anything worth watching.

Quick facts

Water: Water every 5 days. Water when the top third dries, and never leave the pot standing in a saucer of water. Alocasias also drip water from their leaf tips in the morning — that is guttation, and it means the roots are working, not that anything is wrong.
Light: Bright indirect light, as much as it can get without direct sun.
Humidity: 60% and above, or spider mites will find it.
Soil: Chunky and fast-draining: bark, perlite, a little coir.
Feeding: Balanced feed at half strength every second or third watering, spring through summer only.
Repotting: Repot once a year.
Toxic to pets: Toxic to cats, dogs and people if chewed — the sap carries insoluble calcium oxalate crystals, which burn the mouth and throat. Keep it off the floor if anything in the house tastes its way through life. The ASPCA lists Alocasia (Alocasia spp.), the genus as a whole, as toxic to cats and dogs (checked 26 October 2026).
Difficulty: Straightforward.
Mature size: 1.5–2 m indoors; leaves to 1 m.
Native to: Southeast Asia.

Watering a Giant taro

Water every 5 days. Water when the top third dries, and never leave the pot standing in a saucer of water. Alocasias also drip water from their leaf tips in the morning — that is guttation, and it means the roots are working, not that anything is wrong.

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 — more than people give them. An alocasia in a dim room loses a leaf for every new one it makes and slowly winds down to nothing. Direct afternoon sun, though, burns holes in those thin leaves.

Humidity and temperature

60% and above, or spider mites will find it. 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

Alocasias grow from a corm, and a corm sitting in wet compost rots. Use a very open mix and a pot with real drainage. Many growers keep them in semi-hydroponics for exactly this reason.

Feeding

Balanced feed at half strength every second or third watering, spring through summer only. 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 once a year. Once a year in spring. Expect to find offsets — small corms around the parent — which can be potted separately. Do not size up more than one pot at a time.

Common problems

Leaves dropping one after another over winter
Dormancy. Alocasias often go down to nothing and come back in spring.

Fix: Cut the water right back, keep the corm just barely damp, stop feeding, and wait. Throwing it out in February is the usual mistake.

Leaves falling off: how to read it on any plant
Fine webbing, leaves going dull and stippled
Spider mites. This genus is their favourite.

Fix: Shower the plant, wipe both sides of every leaf, and treat weekly for a month. Raise the humidity or they come straight back.

Spider mites: how to read it on any plant
Yellow leaf with a brown mushy stem
Rot at the corm from a wet mix.

Fix: Unpot immediately, cut back to firm white tissue, and repot into bark and perlite.

Yellow leaves: how to read it on any plant
Dry brown patches in the middle of a leaf
Sunburn.

Fix: Move it out of direct sun; the damage does not heal.

Propagation

Separate the offsets at repotting. Each corm, even a bare one the size of a hazelnut, will sprout in damp sphagnum in a covered box over a few 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

The ASPCA lists Alocasia (Alocasia spp.), the genus as a whole, as toxic to cats and dogs (checked 26 October 2026).

If your pet has eaten a plant, call your vet, the ASPCA Animal Poison Control Center on (888) 426-4435, or the Pet Poison Helpline on (855) 764-7661. Both are open around the clock and may charge a consultation fee. Take the plant or its label with you.

This is general information, not veterinary advice. We don't test plants: what we say about toxicity follows the ASPCA's published plant list as it stood on 26 October 2026, and that list can change. "Non-toxic" means not poisonous — a pet that eats enough of any plant can still vomit, and fertiliser, pesticide or leaf shine on a plant can harm it. It also only helps if the plant is what you think it is. It covers cats and dogs only; ask your vet about rabbits, birds, reptiles or anything else, and a doctor about children. Read our terms.

Every houseplant in the library the ASPCA lists as non-toxic to cats and dogs

Named cultivars and variegations

Alocasia macrorrhizos 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
'Stingray'	Alocasia Stingray	every 5 days
'Variegata'	Variegated elephant ear, Alocasia Mac Variegata	every 5 days

Where the variegated forms are grown differently from the plain Alocasia macrorrhizos:

'Variegata'

Huge leaves split with white or cream sectors, sometimes half a leaf white. Unstable, and slower than the plain giant taro. Difficulty: needs attention.

Light: Bright indirect light. The plain plant takes some direct sun; the white sectors on this one burn in it.

Watch for: A new leaf that is entirely white, or nearly. White tissue has no chlorophyll, so the leaf cannot feed itself; it will brown and die early, and it means the stem is drifting towards white. Leave the leaf on while it lasts. If the next leaves are mostly white too, cut the stem back to a node below a leaf with a good share of green.

Watch for: Brown, dry patches on the white parts of the leaves. The white tissue is the weakest part of the leaf and fails first: sun through glass, dry air, or a plant shedding what it can't support. Move it out of direct sun and raise the humidity. The damage doesn't recover; trim it off with clean scissors once it covers much of a leaf.

Questions people ask

How often should you water a Giant taro?

Water every 5 days as a starting point — that is the cadence PlantParlour sets for Alocasia macrorrhizos. Water when the top third dries, and never leave the pot standing in a saucer of water. Alocasias also drip water from their leaf tips in the morning — that is guttation, and it means the roots are working, not that anything is wrong. 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 Giant taro need?

Is Giant taro toxic to cats and dogs?

Toxic to cats, dogs and people if chewed — the sap carries insoluble calcium oxalate crystals, which burn the mouth and throat. Keep it off the floor if anything in the house tastes its way through life. The ASPCA lists Alocasia (Alocasia spp.), the genus as a whole, as toxic to cats and dogs (checked 26 October 2026). If a pet has eaten part of a plant, call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 straight away.

How do you propagate a Giant taro?