Elephant Ear Plant (Alocasia)

Elephant Ear, Giant Taro

Alocasia plants, also known as African mask plants, are tropical perennials that are characterised by large, heart-shaped leaves with pointed tips. Native to tropical and sub-tropical regions of Asia and Australia, these plants are popular for their exotic appearance and ease of care. Alocasia plants can make a great addition to any indoor or outdoor space, and with proper care they can live for many years.

I. Appearance and Characteristics 

Alocasia is a genus of rhizomatous or tuberous, broad-leaved, perennial, flowering plants from the family Araceae. There are about 90 accepted species native to tropical and subtropical Asia and eastern Australia. Around the world, many growers widely cultivate a range of hybrids and cultivars as ornamentals.

The large, cordate or sagittate leaves grow to a length of 20 to 90 cm (8 to 35 in) on long petioles. Their araceous flowers grow at the end of a short stalk, but are not conspicuous; often hidden behind the leaf petioles.

The corms of some species can be processed to make them edible, however, the raw plants contain raphid or raphide crystals of calcium oxalate along with other irritants (possibly including proteases) that can numb and swell the tongue and pharynx. This can cause difficulty breathing and sharp pain in the throat. Lower parts of the plant contain the highest concentrations of the poison.

Prolonged boiling before serving or processing may reduce risk of adverse reactions. Additionally, acidic fruit such as tamarind may dissolve the raphides altogether. It’s important to note, however, that this genus varies in toxicity, and can still be dangerous to ingest, even after taking precautions.

Alocasia are tropical plants that are increasingly becoming popular as houseplants. The hybrid A. × amazonica has gained the Royal Horticultural Society’s Award of Garden Merit. They are typically grown as pot plants, but a better way is to grow the plants permanently in the controlled conditions of a greenhouse. They can tolerate dim light and cannot withstand direct sunlight. They should be cared for as any other tropical plant with weekly cleaning of the leaves, frequent fertilization and medium to high humidity.

They rarely survive cold winters or the dryness of artificial heating, but an attempt to slowly acclimatize plants from the summer garden to the house can help. Once inside, the watering period must be reduced and the plants should be protected from spider mites or red spider attack.

Toxicity

Like all other aroids, Alocasia is toxic to both humans and pets. Due to the calcium oxalate crystals that all parts of the plant contain, they are best kept away from children and animals. If ingested, depending on how much, they can cause eye irritation, mouth irritation, tongue swelling/irritation, swelling of the throat, pawing at the face, and possible vomiting. Very rarely, extreme swelling of the upper airway can occur making it difficult to breathe.

The juices from the plant can also irritate your skin, leading to a rash if you are very sensitive, so make sure to use gloves when working with them or wash your hands after handling them. Keep the plant away from children and pets and call poison control, your doctor, or veterinarian if a person or animal ingests a plant leaf.

II. How to Grow and Care

Sunlight

Think of the dappled sunlight which naturally occurs in a rainforest when you consider where to place your alocasia indoors. Bright, indirect light provides the best fuel for your alocasia to achieve its rapid growth.

If you choose a location with too much direct light, your alocasia may suffer from scorched leaves. Scorched leaves may appear as a targeted brown spot on leaves or an overall orange tinge to foliage.

An alocasia kept in a room with too little light may be the answer to the common question, why is my alocasia drooping?

Alocasias planted outdoors thrive in part sun. Choose a spot with direct morning sun and a break from the heat in the afternoon..

Temperature and Humidity

Alocasia will suffer below 60 degrees Fahrenheit. Some varieties will die back during colder weather and re-sprout from the rhizome. They require very humid environments. To raise the humidity around your plant, place it on a tray filled with pebbles and add water until the rises to just below the pebble surface. Keep them away from cold drafts from windows, doors, and air conditioning.

Watering

Alocasia are water-loving plants, but there is a fine line with these plants. You want to keep the soil evenly moist but not soggy. They require less water during the winter months when the plant is dormant.

Allow the top few inches of soil to become nearly dry before watering. This will help keep the soil evenly moist. Soggy soil makes the plant susceptible to fungal infections and root rot.

Soil

Plant alocasia in a loose, well-drained potting mix. They have a preference for slightly acidic soil, which is provided by a standard all-purpose peat-based potting mix or one specially formulated for aroids. These plants don’t like wet feet, so if you need to improve the drainage, you could amend the mix with orchid bark or perlite.

Fertilizing

A liquid houseplant fertilizer with a 20-20-20 formulation is recommended during the growing season. This general-purpose mix contains 20% each of nitrogen, phosphorus, and potassium to promote healthy foliage growth and strong roots. Dilute it to half-strength to reduce the risk of leaf burn, or opt for a slow-release variety that gradually releases the nutrients.

These plants, especially larger specimens, are heavy feeders. So feeding once or twice a month while the plant is growing is a sensible strategy. Stop feeding your alocasia during its dormant phase.

Pruning

Only prune your alocasia to remove damaged, dying, or dead foliage. Doing this will allow the nutrients to head to the healthy foliage, helping it flourish. It’s best to prune your alocasia when it is actively growing in the spring or summer.

Use sterile, sharp pruning shears or scissors to cut the stem of the flawed foliage at the base of the plant. Because of the plant’s toxicity, use gloves when pruning this houseplant.

Propagation

Division

You can propagate most alocasia plants by clump or rhizome division, something that’s easy to do and will produce many more plants. Perform this task in the spring.

  • Use a trowel to gently dig your plant out of its container and choose root clumps that have gotten bigger over time, ensuring plenty of rhizomes to divide.
  • With clean pruners, cut off pieces of the underground rhizome and pot them up separately in a moist potting mix.
  • Keep pots warm and moist until new growth begins, usually a couple of weeks. They are ready to be potted when you tug at them and they have enough roots to resist.

Seed

This plant is very easy to propagate by root division, so propagation by seed is not frequently done. But if you have a mature plant that flowers and produces seed pods, you can extract the seeds from the dried pods and plant them in a rich, peat-based potting mix. Sow the seeds on the surface, then sprinkle a thin layer of potting mix over them. Keep the potting mix damp but not soggy until they sprout.

But be patient because it can take years to nurture seedlings into full-sized plants with the characteristic huge leaves.

Pests and Diseases

  • Common Pests & Plant Diseases

Alocasia plants are not commonly victims of disease. However, most alocasia species are prone to spider mites. Their large leaves are also at risk of being torn by strong winds, so keep them in a protected area, especially during storms.

  • Common Problems With Alocasia

Alocasia are easy plants to grow, if they receive the amount of light and water they need to thrive. Hopefully, these fixes will help.

Yellowing leaves

There are several reasons why your alocasia leaves have yellowed. It’s likely a watering issue—too much, or possibly too little, can cause leaves to discolor this way. Alocasia drink a lot; several inches of water a week. If you’re giving them less or more, that might be the reason for the yellowing.

They also need a good amount of filtered light, and if they’re receiving less than the desired amount, this can cause leaf yellowing. Their leaves can also turn yellow if they’re growing in a pot that is too small. When was the last time you replanted? Are they pot bound? Repotting might be the answer.

Shriveled or drooping leaves

If your alocasia is suffering from drooping leaves, you are likely getting it wrong with watering, light, or fertilization. These plants need even moisture, so change your watering habits if the soil is soggy or too dry. Move your plant to a spot with brighter indirect light if it is located in a shady corner, and consider feeding more regularly if your fertilization schedule is lax.

III. Alocasia varieties: Best types of Alocasias

Around 100 species of Alocasia plants are available, and most of them can be kept as houseplants. Nearly 90 accepted species of Alocasia are found in tropical and subtropical Asia and eastern Australia.

Some of the varieties are mentioned below:

  • Longiloba (Tiger taro): This variety of Alocasia plant has dark greyish, green foliage with white veins. It reaches a maximum height of around three feet.
  • Macrorhiza (Giant taro): Macrorhiza is among the popular and largest houseplant varieties of Alocasia. It grows up to 15 feet in height with three-to-four-feet long leaves.
  • Amazonica (Polly alocasia): Amazonica species of Alocasia is a compact 18-inch plant and characterised by wavy, arrow-shaped red leaves.
  • Cuprea ‘Red Secret’: This variety is three-feet-tall and knowns for its metallic bronze-red leaves.
  • Alocasia ‘Zebrina’: This is a hybrid variety that grows to have arrow-shaped leaves and leggy, zebra-like stalks. Typically, it exists as a small plant and may grow large over a period.
  • Reginula ‘Black Velvet’: This is a compact variety known for its dark green leaves and white veins and grows up to 18 inches in size.
  • Alocasia amazonica ‘Bambino’: This is a dwarf variety of the Alocasia plant, which reaches a maximum height of 12 inches. The growing conditions of this plant are similar to those of other varieties. It can thrive in high humidity.
  • Alocasia amazonica ‘Ivory Coast’: This is a fast-growing variety of the plant, which grows up to a maximum height of 30 cm and width of 20 cm.
  • Alocasia micholitziana ‘Frydek’: Alocasia Frydek is another popular variety of the Alocasia plant and thrives in optimum levels of water, light and soil. Make sure the plant receives adequate moisture and regular watering. It thrives well in high humidity levels.

Elephant Ear Plant (Alocasia) Details

Common name Elephant Ear, Giant Taro
Botanical name Alocasia
Plant type Herbaceous Perennial
Hardiness zone 10a, 10b, 11a, 11b, 12a, 12b
Growth rate Fast
Height 2 ft. 0 in. - 9 ft. 0 in.
Width 2 ft. 0 in. - 9 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Cream/Tan
Leaf color Variegated