The Giant Elephant Ear plant is a striking and easy-to-grow foliage plant that can create some dramatic effects when landscaping the tropical garden. In some countries it’s commonly known as the Giant Taro, but taro is actually a species of Colocasia, whereas the Giant Elephant Ear plant is a species of Alocasia.
Its botanical name is Alocasia macrorrhiza and it can be found growing wild in many parts of tropical Asia where it sometimes grows up to five metres high. It’s now widely cultivated throughout the tropical world where in ideal garden conditions it can grow to about 3-4 metres high.
They are fast growing, so ideal for people landscaping a new garden in the tropics who want to give the garden an immediate tropical feel. However, when young they won’t tolerate full sun, so they are not suitable for planting in bare spaces unless you have some shade from established trees or a building.
The Giant Elephant Ear plant does produce flowers, but they are fairly insignificant, somewhat similar to those of a calla lily. Landscapers of new gardens primarily use the plant in conjunction with palm plantings to create a lush tropical look. They require quite a lot of water and high humidity all year round, so they are not suitable for dry tropical regions.
To get your Giant Elephant Ear plant looking as lush and green as they are in the wild, here are some growing tips:
Giant Elephant Ear plants grow best in bright, indirect sunlight. They will tolerate direct morning sun, but much prefer dappled or filtered sunlight from established trees. If you don’t have large trees in your garden, then plant them close to the house on a side which doesn’t receive direct afternoon sun.
It is possible to grow them as feature plants in full sun in regions that don’t have a long dry season or at elevation, but that’s only if all the other growing conditions are perfect, especially in respect to soil and drainage. During the dry season the leaves may become scorched, but the plant will quickly recover as soon as the rainy season starts.
Giant Elephant Ear plants will grow in almost any type of soil, but they won’t grow large and lush unless the soil is very well drained, rich in organic matter, and slightly acidic. The best growing medium is a sandy potting soil with lots of well-rotted compost added to it.
If you are doing large scale plantings of the Giant Elephant Ear plant, and your garden soil is clayey, dig in as much gypsum as you can to improve drainage as well as lots of well-rotted buffalo or horse manure. It’s worth hiring a rotary hoe to do that if you have a large area to plant out. Add some bales of peat moss if your budget will accommodate it.
Giant Elephant Ear plants need to be kept moist all the time, but not waterlogged. That’s why it’s so important for the soil to be well-drained. Growing them in raised garden beds or on a slope are ways to ensure that they won’t become waterlogged and susceptible to root rot.
To prevent the soil from drying out, mulch the soil around the plants with whatever materials are available locally. Pine bark looks attractive but can be expensive for large areas. Sugar cane mulch is a cheaper alternative that does the job just as well. Rice hulls will undoubtedly be the cheapest mulch available in rice-growing areas, but they can get washed away in heavy storms.
Giant Elephant Ear plants are fairly heavy feeders and need to be fertilised regularly to keep them looking green. They are not fussy about the type of fertiliser and respond well to both organic and inorganic fertilisers. If using chemical fertilisers, choose a general purpose NPK type that has a higher N (nitrogen) level than P (phosphorus) and K (potash). An NPK fertiliser with added trace elements is even better.
Blood and bone is an excellent organic fertiliser and you can also use any of the water soluble organic fertilisers on the market such as the seaweed-based ones or fish emulsion – although the latter may work out expensive for large plants. Making your own liquid organic fertiliser by steeping animal manure in drums is a cheaper alternative.
Fortunately Giant Elephant Ear plants are not prone to many pests and diseases. Large grasshoppers chomping away at the succulent leaves is the main pest that you’ll have to deal with. They won’t harm the plants but will leave large holes in the leaves making them less attractive. Remove them by hand when you spot them.
Mealybugs, aphids or spider mites may occasionally attack the plants, but if the plants are large and vigorously growing, they won’t do a lot of damage. If any of those pests do get out of hand, it’s best to prune away and dispose of the affected leaves. Spraying with white oil can help protect the younger leaves from further infections.
In the dry season, if leaves start browning around the edges, it’s best to remove them by pruning at the base (if the stem of the leave is too large for pruning shears, use a sharp knife) as this will help the plant to concentrate its energy on keeping the younger leaves green and strong.
The sap of the Giant Elephant Ear plant is toxic to dogs and cats, but pets are unlikely to start chewing on the leaves as they won’t find them palatable. However, it’s best to keep your pets away if you are pruning old leaves back to ensure that any sap dripping from the stems won’t get onto your pets.
The positioning of Giant Elephant Ear plants is important when landscaping a new garden. Aside from the sunlight requirements, it’s best to plant in sheltered areas to protect the plants from strong winds which can damage the leaves. Leaf damage from the wind won’t hurt the plant – it simply makes the plant look less attractive.
And don’t underestimate the size to which the plants can grow, so give them plenty of space between plants so they are not constricted in their growth by the root systems of the adjacent plants. Giant Elephant Ears don’t have aggressive root systems, so they can be safely planted next to houses or swimming pools.
As the plants grow larger, they may produce small new plants (known as ‘pups’) at the base. Depending on your landscaping objectives, if you want a bushy jungle effect, then you can let the pups grow – but as the plant will be putting energy into supporting the baby plants as well, the size of the mother plant may not reach its full potential.
However, if you’d like to use the pups to propagate more Giant Elephant Ears to plant elsewhere in the garden or giving to friends, they can be removed for replanting. It’s best to let the pups grow until they are about 20-30 cms high before removing to make sure they have developed sufficient roots.
Divide the pup from the mother plant with a long sharp knife or machete, cutting at a slight angle towards the base of the mother plant to ensure that you retain as many roots on the pup as possible. Before transplanting, remove about half of the leaves on the pup to reduce the stress on the baby plant.