The common plant name “elephant ears” is used for several different plants.
One of which is Colocasia esculenta.
In addition to elephant ears, it is also referred to as the taro plant.
It gets this name from its underground corms or “bulbs” known as taro, which are edible and popular in many parts of the world.
It is grown as a food crop in Hawaii.
Colocasia is known for its large heart-shaped or arrow-shaped leaves that can resemble and reach the size of an elephant’s ear.
These large leaves create an impressive tropical display.
Elephant ear Colocasias are available in different leaf and vein colors- bright green, purple, dark green, and burgundy-black.
These add strong contrast and interest to any garden design.
How Big Does Colocasia Grow?
Colocasia thrives on a warm, humid environment and moist soil.
When given these conditions, the leaves can grow to 24 inches or more in size.
The overall plant height (depending on the variety) can reach 24-40 inches.
Can Colocasia Grow Inside?
Colocasia can be grown indoors as a houseplant.
They may need supplemental humidity from a humidifier or vaporizer to avoid brown edges on the leaves.
In addition, Colocasia requires a lot of light, but direct, full sun may burn leaves.
It may experience an annual dormancy period in the fall in which the leaves die back.
This is a normal part of its growth cycle.
During this period, reduce the watering frequency and the plant will grow new leaves once the dormancy has ended.
How to Grow Colocasia Outdoors
Because of their size, most Colocasias are grown outside either in garden beds or in large containers.
They make ideal “thriller” plants for containers and statement anchor plants for a garden.
Depending on the variety, they are hardy to approximately U.S. zones 7b and higher.
When grown outdoors in northern climates, the corms must be dug and stored for the winter to “save” them for the following season.
They can be planted outside again once the chance of frost has passed.
There is at least one large pinkish-white “eye” on the corm from which new growth will emerge.
Plant that side facing up.
Since Colocasia elephant ear plants don’t like cold temperatures or cold soil, it’s generally advantageous to start the plants indoors or buy the plants in full leaf from a greenhouse.
How to Care for Colocasia
Elephant ears are native to tropical regions so they grow best in a warm, humid environment.
The roots need to stay evenly moist and they should not dry out.
Some varieties can be grown as water plants in a pond.
However, there is always a possibility of root rot so the plants must be monitored closely.
Most Colocasias prefer part sun to some shade.
In hotter climates, afternoon shade is ideal.
The brighter green the leaf color, the more sun it can tolerate without leaf scorch.
Use a slow-release fertilizer every 3 months or a water-soluble fertilizer every 2-3 weeks during the growing season.
Do Colocasia Flower?
A Colocasia does produce a flower when they have a lot of light.
This is rarely the case when grown indoors.
However, the flower isn’t showy and the plant is prized for its foliage.
Is Colocasia Poisonous?
Yes, all parts of the plant are poisonous.
However, if the corm (taro root) is cooked properly to break down the toxic compounds, it can be eaten.
Keep Colocasia plants away from pets and children.
Is Colocasia Invasive?
Several U.S. states have classified Colocasia esculenta as an invasive species.
Click here to learn more.