Alocasia, or the African Mask Plant, or Kris Plant, is a stunning perennial with its origins in the Philippines. It’s usually sold as mature plants in garden centres around Australia, and thanks to its worldwide popularity is often sold as a houseplant.
In this article, I want to share tips and tricks for how to grow Alocasia both indoors and out, as it can make a striking addition to beds, borders and pots with the right care.
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Alocasia Plant Details
Alocasia are native to subtropical Asia, but have naturalised in Eastern Australia. Their leaves go completely dormant in winter as a reaction to changing light levels, and while the rest of the world is limited to growing them indoors, so long as they have protection from frost, they are an exceptional choice for the garden throughout most of Australia.
African mask plant come in a huge variety of colour and leaf forms, but all subgenuses share one common visual trait which has made them unwaveringly popular plants under cultivation for decades.
The most well-known variety is A. Amazonica, with dark green foliage punctuated by bright green, almost white, midribs and veins along the leaf surface, with the exact opposite colouring seen in the similarly formed leaf of Alocasia Silver Dragon.
For me, it’s the delicate A. Zebrina that earned its space in my garden. While it takes a little more care, and it is more prone to root rot and damping off than any other subgenus of Alocasia, Zebrina has a true lightness, both to touch, and to look at.
It’s striped stems give it its name, and while it might be less in your face than others with stronger midribs, and sturdier stems, it pairs with pretty much any other plant, whether you’ve got towering annuals spouting from under its low canopy, or delicate spring bulbs pre-empting it’s summer display.
Alocasia Varieties
Alocasia Brisbanensis
Alocasia brisbanensis are native to the rainforests of Eastern Australia, so grow well in most outdoor spaces across the country.
They are one of the larger varieties of Alocasia, growing to 7.5 ft. tall at full maturity so add a unique structure to any shaded garden bed with their thick petioles giving a weight to the leaves that is unusual in most other forms of Alocasia.
The leaves of Alocasia Brisbanensis are a grassy-green, and their stems come in two types; dark stemmed, and light stemmed Brisbanensis.
Get to know more about the in our Alocasia brisbanensis Australian native guide.
Alocasia Amazonica Polly
Alocasia Amazonica Polly are probably the most popular, and certainly the most common species, due to their relative toughness compared to all others, but also because (despite all the efforts of breeders) remain one of the most visually striking.
Alocasia Zebrina
Zebrina have gloriously delicate striped stems, which can suffer easily from over-watering, and need dappled light to avoid leaf burn.
They scorch easily and really are very fussy plants, but they have a delicacy and a lightness to their leaves that can’t be compared to any other plant in the garden.
I always think they look like a Hosta and a Fritillary had a baby – there's a grace to them, but equally a punch.
Alocasia Silver Dragon
Source: Evergreenseeds.com
Silver Dragons are one of those plants that look like they belong in sci-fi. There are plenty of silver leafed plants out there, and they develop naturally to cope with bright light.
As a result, these make excellent plants for full sun, as they are far less likely to scorch than other Alocasia. They are very susceptible to over watering though.
And thanks to their already pale leaves are less likely to give any early indications, so the first you’ll know about your Silver Dragon being unhappy is when it’s leaves turn brown and start dropping off.
Alocasia Azlanii
Source: Sunnyside-gardens.com
Azlanii are a vivid burgundy, almost blood red foliage plant, far more reminiscent of European forest floor plants than most subtropical plants.
They are a product of exceptionally skilled cultivation, and while they are quite susceptible to over-watering, we’ve found them to be more resilient than most Alocasia here.
They’re also sparingly happy in bright light despite their dark foliage, but it's safer to place them somewhere with a little bit of dappled shade.
Alocasia Macrorrhiza Stingray
Source: Plants.rainbowgardens.biz
I wanted to include stingray as an example of how we learned what not to do with African mask plant. Stingray are the closest Alocasia to most other plants from the subtropics, with thick, but not overly sturdy leaves, and a rich green all over their stems, petioles and leaves to maximise photosynthesis.
They are exceptionally happy in dry, humid conditions, but want to be under the canopy of subtropical trees and shrubs as much as possible.
Temperature is crucial here, not light, as light can easily scorch green leaves, and Alocasia are exceptionally bad at recovering from illnesses.
Other Alocasia Varieties
Kris plant have dozens of subgenuses, far too numerous to describe each in detail, but those above are the most likely to be found in garden centres, whether as corms or as mature plants.
There are some truly beautiful varieties, and if you’re thinking of starting a serious collection it’s worth looking out for the rarer species like Alocasia Dragon Sale, Cuprea Red Secret, or the elongated (in name as well as leaf) Lauterbachiana Purple Sword.
How to Propagate Alocasia
African mask plant rarely flowers, so propagating from seeds, and particularly finding the right conditions to ripen the seeds is almost impossible.
If you ever have the good fortune to have a flowering Alocasia, and subsequent seeds, propagation is easy. Simply place the seeds on a bed of tropical seed compost, and water from the base.
Leave undisturbed and cross your fingers as germination can be erratic. Once sprouted, wait until leaves form, then gently pot the roots into a small pot and treat like any other Alocasia.
However, propagating Alocasia from seed is both unlikely and impractical, especially when you know how easy it is to grow them from split clumps.
African mask plant are tuberous, meaning they grow from a set of roots that sprout from a central rhizome (a rhizome is thick root that stores energy like a bulb, but rather than storing energy for spring, it remains dormant through winter, then sends new roots, which later form their own rhizome.
Propagating Alocasia from Division
African mask plant is really easy to divide. When you see new stems shooting up from around the base of the original plant, these are in fact young plants in themselves.
By simply tipping the pot out gently, you can pull the young plants away from the main root, and make a clean cut against the rhizome. This will quickly heal underground and won’t harm the original plant.
The new plant will quickly form its own root system and respond to the separation by growing its own rhizome much faster than if it were left to rely on its parent.
With most tropical plants (Check out our list of tropical plants you can grow in Australia), we’re used to propagating by planting cuttings in water as our cuttings are therefore less likely to develop root rot in their early days (this is due to the unique water roots that plants send out when they are propagated hydroponically).
However, for any plants propagated from root cuttings, or division it is much safer, and produces much stronger plants in the long run to immediately place the young plants in the soil you intend to keep them in.
When young plants are given just water for propagation they don’t send roots in search of water, and they don’t develop resilience to diseases.
A plant grown in soil is always stronger, and plants from root cuttings are much more likely to become too reliant on readily available water.
How to Grow Alocasia
Alocasia don’t like damp conditions, but require plenty or regular water for healthy foliage, so well drained compost, or well drained soil is essential for their health. But mixtures with good water retention are equally crucial for success.
In this guide we’ll explore positioning as well as soil mixes in full, to make sure you give your plant the right start in life.
When to Plant African Mask Plant
African mask plant are dormant in winter as the shorter days don’t provide enough light for them to thrive, so don’t worry if you see them starting to drop leaves in autumn, this is normal.
You can plant Alocasia all year round, but as with any deciduous perennial, it’s important to give it the most help you can, which means the best time to plant is in spring.
Ideally a few weeks after temperatures are reliably over 10 C to avoid any risk of cold shock to the plants, which should be covered up, or fleeced if you grow them outdoors in winter.
Alocasia Light Levels / Positioning
This plant needs bright but indirect light, but please don’t confuse indirect light with low light. If you are growing Alocasia indoors, this is really simple to achieve, place them around 1m away from a bright window, or in the corner of a bright room out of direct sight of the window.
Because all species of Alocasia are very susceptible to leaf burn, they require steady light and protection from the hottest sun, which will quickly brown their leaf tips, and never really recovers in that growing season.
Don’t fret though, as Alocasia are perennial, so even if they lose their vigour and verdancy in summer, they will grow fresh foliage next spring. If your plants suffer leaf burn this year, consider moving them somewhere slightly under the shade of a tree with a loose canopy.
Palms are excellent companions to Alocasia outdoors, as they use most of the moisture in the soil, without completely drying it out, which can reduce the risk of over watering, and also give excellent dappled light.
Soil preference
Alocasia needs well drained soil that holds enough moisture to retain happy leaves. With one species holding leaves that can reach 40-50cm long, they really do need a good drink, but because they hate sitting in water it can be tricky to find the balance through trial and error.
With potting mix, perlite is a good option, as it doesn’t affect soil acidity, and helps water drain without impacting nutrient levels, but pair perlite with a good quality general purpose compost for water retention, and houseplant compost to give it the right nutrient level for an easy tart to life.
If you want to make your own compost, read our guide on our worm farm guide and product reviews for 2022.
If you’re planting in the ground, dig compost and horticultural grit through the soil to aid drainage, and boost nutrients.
Alocasia are rainforest plants from the subtropics, and need high nutrient levels, so mixing good quality compost rather than peat into the hole will help drainage and reduce the risk of waterlogging.
Peat might be high in nutrients but is much more likely to over fill with water in the wet seasons.
Caring for Alocasia
Watering
Alocasia needs regular watering, particularly when grown indoors. While they are fairly drought tolerant, you need to treat them with a sensitivity to their natural habitat.
Sub-tropical rainforests are humid, but not overly wet despite their name. The rain is mostly drunk by trees and larger top layer plants, leaving the ground dwellers like Alocasia to search for their water, never quite drying out, but never getting waterlogged.
Because most of us don’t have rainforests in our backyards, regulating their water retention through soil choice is the best choice for outdoor plants.
For indoor plants, like most houseplants, they should only be watered when the top inch of soil in their container is completely dry using rain water where possible.
Fertilisers
For those of you following NPK level religiously, 20:10:20 is what you need to be looking for on fertiliser labels. Meaning that for every 100ml or fertiliser, it contains 20% active Nitrogen (N), 10% Phosphorus (P), and 20% active Potassium (K).
Nitrogen and Potassium support root and foliage growth, while Phosphorus promotes flowering and fruit, which is irrelevant with this foliage focused beauty.
However, if you prefer playing it by ear, mixing a healthy amount of garden compost into the planting hole will add more than enough nitrogen and potassium to get your Alocasia going.
For ongoing care, coffee grounds and eggshells are good ways to keep Alocasia happy, and mulching with multipurpose compost in early winter to protect the rhizomes from frost is a useful way to add nutrients too.
More on fertilisers: Complete Australian Garden Fertiliser Users Guide
Pruning Alocasia
Alocasia doesn't need any regular pruning. They are deciduous perennial foliage plants so will die back to the ground in winter, and re-sprout. The only reason to prune them is to remove any dead, damaged or diseased growth.
Otherwise, leave them well alone and they will happily get on with their lives without intervention.
Common African Mask Plant Pests and Diseases
Alocasia don’t have any notable essential oils, which means they are much less attractive to pests than most sub-tropical plants, and certainly unlikely to be affected if grown alongside flowering tropicals.
This will almost definitely have more or a drawn to mites and scale, but every so often, these irritating pests find their way onto the steams and leaves of our favourite Alocasia, and there’s only a handful of ways to deal with it.
Spider Mites
Signs
Spider mites spin webs, just like any other arachnid, but rather than growing them to catch prey they spin them to protect their eggs. If you ever see small clusters of silk patches on the underside of leaves, it is likely the work of spider mites.
When the problem gets worse you’ll notice strands of silk between the points of each leaf – or for serrated Alocasia, strings between the serrations on the leaf.
Early signs of spider mites, particularly in summer, are dry leaves despite wet soil. Spider mites don't feed on living prey, instead they suck out the chlorophyll from the cells in the leaves, usually of dryer plants, leading them to appear dry, and starved of water.
So even if soil is well watered, the plant isn’t getting enough water to keep up with the unquenchable thirst of the spider mites.
Treatment
Neem oil really is the only effective treatment of spider mites. They thrive in dry conditions, so can be exacerbated by under watering, or over-drained soil, and are likely on indoor Alocasia due to our predisposition towards keeping them dry and in part shade.
Neem oil, either diluted and sprayed, or applied directly to spider mites will kill them instantly, and also help resolve any unnoticed fungal issues that they might have caused.
Mealy bug
Signs
Spotting mealy bugs on your Alocasia is fairly simple, they’re really distinctive white pests that gather in clumps, looking almost like an occlusion to the stem just below a leaf.
They can gather on leaves and are often mistaken for spider mite egg clusters, but their groupings are usually fluffy rather than silky.
Treatment
While regular treatments of mealy bug include insecticide or alcohol treatment, I’ve found that most houseplants will always have recurring problems when they have had one infestation.
The easiest way to eradicate the problem is to use a hand held hoover and literally suck the mealy bugs off your plants.
I know it sounds extreme, but a basic car hoover will do the trick and as long as you’re careful and have a steady hand will not only take them off stems and leaves, but remove most of the problem from the soil too.
Obviously, you’ll need to re-mulch afterwards. For more on mealybugs, here is more on how to get rid of mealybugs.
Root Rot
Signs
Root Rot is usually a sign of overwatering or, sadly, that Alocasia has been poorly cared for by the garden centre you purchased it from, and sold with existing infections that have yet to appear.
Early signs of root rot in Alocasia are browning leaf edges that taper into yellow into the centre of the leaf. The brown can be mistaken for scorch, but when paired with yellowing leaves (on any Alocasia variety) it’s a sign of a plant that has been sitting in saturated soil.
The yellow is a sign of saturation, while the brown is a sign of the root’s inability to take up nutrients.
Treatment
With any case of root rot, it’s important to remove the affected roots before fungus spreads. Thankfully, Alocasia has tough roots so don’t mind root pruning when it's needed.
Their roots are surprisingly slow growing for rhizomes, so don’t get carried away and only take off what is showing signs already. By taking too much root away, you’ll likely slow down the top growth.
Also, unless it’s a really serious case that requires immediate attention, don’t prune Alocasia roots in winter. They should be pruned in spring or summer, so they have a chance to regenerate during the growing season.
If you notice early signs of root rot in autumn or winter, stop watering, and move the plant to a sunnier position for a few weeks. The heat can kill the fungus, but won’t remove the problem.
This won’t resolve it, but it will buy you time until spring when you can tackle the infection more effectively.
Sun Scorch and Leaf Burn
Signs
If your Alocasia is turning brown, there are two most common causes – sun scorch and over feeding. Both lead to a burnt appearance, either like the plant has been literally frazzled by the heat of the sun, or like the roots are taking up too many nutrients.
And just as we would get heart burn, leading to irritated and over stimulated leaves that brown in much the same way as sun scorch. In both cases, re-thinking your care is required, and both are easy to treat.
Treatment
Leaf burn on Alocasia is unlikely to recover in the growing season, so it's best to just leave it in place and move the plant to a new location where it is in less direct sunlight.
The affected leaves will fall in late autumn and be replaced by new growth in spring. If the brown tips are particularly offensive, and only appear on one or two leaves, there’s no harm in trimming them off.
However, it’s not necessary as the damage isn’t infectious, and won’t spread to other parts of the plant.
African Mask Plant FAQs
How do you make Alocasia grow big?
Each species has its own limitations, but high Nitrogen and Potassium fertilisers added via a slow release granular fertiliser, mixed with some used coffee grounds will help increase foliage health, and size.
Also, using Red/Blue grow lights promotes leaf production, so might be worth investing in.
How do you water African mask plant?
Alocasia needs regular water, but should never be watered if the soil is at all damp top touch on its surface. If you grow Alocasia outdoors in Australia, then ensuring it has enough drainage in the planting hole when planting out is essential.
Does Alocasia need sun?
Yes, Alocasia are sub-tropical plants, and despite being forest floor plants, require bright but indirect light to thrive. They are delicate plants though, so never put them in direct afternoon sun, as they will almost certainly suffer from sunburn.
Can you grow Alocasia from cutting?
Leaf cuttings and stem cuttings won’t work with Alocasia. They can be divided from its root ball by separating young plants from the base of their parent, either by cutting a small section of rhizome and root, or by gently pulling a section with its own root system.
Wrapping Up Our Alocasia Growing Guide
I never know how personal to be when I’m writing these guides, because let’s face it, it’s not important to you to know that we call our Alocasia Zebrina, Sebrina (we name all our house plants).
What’s important is that throughout our guides to growing tropicals and subtropical plants in Australia, we’re sharing our experiences of success and failure, so you know how to tweak your Alocasia care.
Whatever we’ve shared here though, please don’t let it put you off. Alocasia might be fussy plants, but once you know how to care for Alocasia, they become like part of the family, as any house plant does, and grown indoors, or outdoors, are undeniably as beautiful as they are varied.
