Colocasia esculenta (taro or elephant ears) is grown for its huge and velvety heart-shaped leaves in shades of lime green, purple or black. A tender perennial, it can be grown outside in the UK in summer, in a pot or in a border, where it looks especially good combined with other jungly, exotic-looking plants such as bananas, begonias or tree ferns. It loves moist soil, so it can also be grown around the edge of a pond.
Thought to have originated in south east Asia, taro (also known as cocoyam, dasheen, godere and eddo) has been cultivated as a food crop in many parts of the world for centuries. It is grown for its edible tubers (which taste similar to sweet potatoes or yams) and leaves. It is grown in wet, swampy areas and paddy fields and is one of the few crops that will grow on flooded land.
You can also grow colocasia indoors all year round, as a house plant. Although evergreen, the foliage is likely to die down if temperatures dip below 21°C. All parts of the plant are poisonous if eaten raw, and may cause skin irritation.
How to grow colocasia
Colocasia needs plenty of warmth, humidity and moist soil to thrive. Outside, grow in dappled shade, in moist, rich soil in a sheltered spot and bring back indoors in autumn. If growing as a house plant, give it bright but indirect light and a humid atmosphere. Wherever you are growing it, apply a balanced liquid fertiliser (such as seaweed) feed monthly when in growth, and keep the soil moist.
Colocasia: jump links
Where to grow colocasia
If growing outside in summer, plant in dappled or partial shade in moist soil, in a sheltered spot.
If you're growing your elephant ears as a house plant, it will need bright but indirect light and a humid atmosphere – a steamy bathroom or conservatory is ideal. Your plant will lose its foliage in winter if temperatures go below 21°C.
How to plant colocasia
If you're planting a colocasia plant in the ground, wait until the last frosts have passed in late spring before planting out. Add lots of organic matter to the planting hole, which should be the same size as the root ball, and water in well.
If you're planting a colocasia in a pot, choose a large container (around 25cm across, with drainage holes) and plant into peat-free multi-purpose compost.
If you're planting colocasia corms in a pot, plant them with the pointed side (or the end with the most concentric rings) facing up. The tip of the tuber should be a couple of centimetres below the soil surface. Place on a sunny windowsill or in a warm greenhouse.
Caring for colocasia
Wherever you are growing your plant, apply a balanced liquid fertiliser, such as a seaweed feed, every month when it is in growth, and keep the soil moist.
Your colocasia will not survive frosts, so in autumn, treat the tubers as you would those of dahlias – dig the plant up, cut off the foliage and store the tubers in a cool but frost free and dry place over winter. Replant the tubers and bring them back into growth in early spring the following year in a warm place indoors or in a greenhouse.
If you're growing your colocasia in a pot, bring it indoors and enjoy it as a house plant over winter. You'll need to keep it at temperatures that are above 21°C, otherwise it will go dormant and lose its leaves. Water sparingly in winter.
How to propagate colocasia
Colocasia is grown from corms (bulbs). For best results plant the corms in a large container (around 25cm across) indoors or in a greenhouse, in spring.
Fill the container to three quarters with a peat-free multipurpose compost
Position the corm with the pointed end (or the most rings) facing upwards. Top up the container with more compost, making sure that the tip is just covered
Water in thoroughly and place in a warm spot indoors
Harvesting and uses
If you're growing taro to eat, harvest the tubers in autumn, when the foliage starts to die down - they can be boiled or fried like potatoes. The leaves can be harvested all year round but don’t strip the plant of foliage. The tubers don't store well, so eat them within a few weeks.
Growing colocasia: problem solving
The young leaves can be attractive to slugs and snails, so be sure to protect them.
The tubers may rot if the the soil is too cold and wet in spring.
If the leaves are turning yellow, there may be a problem with watering or feeding, so check that you're giving your plant the right care. Alternatively, the plant may be going dormant in autumn, which will happen if the temperature goes below 21°C.
Best varieties of colocasia to grow
Colocasia esculenta ‘Black Magic’ – eye-catching black, velvety leaves Height x Spread: 1.5m x 1.5m
Colocasia esculenta ‘Illustris’ – very dark foliage with prominent green veins H x S: 1m x 60cm
Colocasia esculenta 'Mojito' – bright green leaves speckled with black H x S: 1m x 75cm