Tropical plants in the Alocasia genus feature stunning foliage that can become the centerpiece of a garden or room. In the right conditions, they can grow very fast, but they are also sensitive plants. Alocasia grows well in containers; they can thrive outdoors in the summertime and then be brought indoors to overwinter. Some species are considered invasive, especially along the gulf coast of the United States. Thus, verify with your local municipality before planting this species outdoors. If you have children or pets, you might want to avoid these plants because the leaves are toxic to humans and animals.
|Common Name||Alocasia, Elephant Ears, African Mask|
|Plant Type||Tropical plant grown as a houseplant in non-tropical climates|
|Mature Size||Size ranges based on variety from 2 feet tall and 2 feet wide to 15 feet tall and 8 feet wide|
|Sun Exposure||Bright indirect light indoors; part shade outdoors|
|Soil Type||Loose, well-draining potting mix or crumbly loam|
|Soil pH||5.5 to 6.5|
|Bloom Time||Spring and summer|
|Flower Color||Light butter yellow|
|Hardiness Zones||10 and 11 for outdoor plants|
Watch Now: How to Grow and Care for Alocasia Plants
Alocasia Plant Care
Even with a short growing season in northern climates, these plants can grow rapidly. In the warm summer months, alocasia can produce a new leaf every week. Each new leaf might be twice the size of the previous week. The leaf shapes can vary from slim arrowheads to wide heart-shaped leaves. They have colorful veins and a variety of textures from thick, waxy, slick, and glossy.
Once the plant is in its dormant period (in the late fall and winter), it will begin resting. The rapid leaf growth will stop and the plant will likely remain as-is throughout the winter season. Continue to care for it, and the rapid growth will return the following growing season.
Needs vary from shade to full sunlight, depending on the variety. Ask the grower or seller if the plant is sun-trained. Leaf color tends to be better among plants that grow best with more light.
Plant in loose, well-drained potting mix or a crumbly loamy soil. 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.
Keep Alocasia plants moist all year; they are water-loving plants. There is a fine line with these plants. You want to keep the soil moist, but not soggy. They require less water during the winter months because the plant is dormant.
Temperature and Humidity
Alocasias will suffer below 60 degrees Fahrenheit. Some varieties will die back during colder weather and re-sprout from the rhizome. They require and thrive in very humid environments. To raise the humidity around your plant, place it on a tray filled with pebbles and then add water until it rises to just below the bottom of the pot. Keep them away from cold drafts from windows, doors, and air conditioning.
Alocasias can be heavy feeders, especially large specimens. Feed with liquid fertilizer during the growing season or frequent, small applications of granule fertilizer.
Potting and Repotting
Repot Alocasia varieties annually into larger pots with fresh, free-draining potting soil. Also, it's best to divide the rhizome annually to keep the plant a manageable size and increase your collection.
Propagating Alocasia Plants
Most Alocasia plants can be propagated by clump or rhizome division. Cut off a piece of the underground rhizome and pot it up separately. Keep it warm and moist until new growth begins.
Varieties of Alocasia Plants
There are about 70 species of Alocasia, as well as dozens of hybrids. Alocasia plants are primarily hybridized because of the appeal of their leaf form, color, and size. Some include:
- Alocasia sanderiana, also known as the Kris plant, has extremely dark green foliage and provides an exotic-looking houseplant. Its long, pointed leaves are have white veins and scalloped edges outlined in white.
- Alocasia x. amazonica is a hybrid that features leathery, wavy-edged, arrowhead-shaped, dark bronze-green leaves (up to 16” long)
- The truly enormous Alocasia macrorrhizos, also known as Giant Taro, can grow up to 15 feet tall and eight feet wide with leaves can reach three to four feet long and two to four feet wide.
Additionally, the plant has been extensively hybridized. Most Alocasia species will survive in shade, but they often appreciate slightly brighter filtered sunlight. The bigger varieties can be trained to handle the full tropical sun. Keep all species warm, moist, and humid. Trim away faded leaves. Like all aroids, Alocasias flower with a typical spathe and spadix, but the flower is usually unremarkable.
Toxicity of Alocasia Plants
The Alocasia is a very poisonous plant; the leaves contain insoluble oxalate crystals.
A human or pet chewing or biting into a leaf releases the crystals which can cause swelling and irritation of the mouth and GI tract. Very rarely, extreme swelling of the upper airway can occur making it difficult to breathe. 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.
While quite striking, these plants can be quite sensitive. A variety of diseases including crown, stem, and root rot, leaf spot, and Xanthamonas are particularly common with alocasia plants. Signs of diseases are typically black or dark brown spots on the leaves and a yellowish rim around the spots. You can prevent disease with proper watering practices; do not overwater these plants. Keep the foliage dry and provide proper air circulation around and near the plant.
Common pests of the Alocasia plants are mealy bugs, scale, aphids, and spider mites. Every few weeks, spray the plant with warm soapy water to prevent these pests and keep the plant dust-free. If an infestation occurs, use an ultra-fine insecticide oil or Neem Oil. These products will kill the pests and their eggs.
Alocasia. American Society for the Prevention of Cruelty to Animals
Alocasia (group). Missouri Botanical Garden
Robène-Soustrade Isabelle, et al. Specific Detection of Xanthomonas Axonopodis Pv. Dieffenbachiae in Anthurium (Anthurium Andreanum) Tissues by Nested PCR. Applied and Environmental Microbiology, vol. 72, no. 2, 2006, pp. 1072–1078., doi:10.1128/aem.72.2.1072-1078.2006