Also known as Elephants Ears, Colocasia put on an impressive show of large, heart-shaped leaves which unravel continuously, one after another throughout the summer. You won’t believe how much can grow out of one bulb! Each large leaf is held at the top of a sturdy upright stalk, forming a strong and stately plant. Grow them as an impressive summer annual and create a real talking point in the garden. These fascinating plants are marvellously exotic - if you’re creating a tropical planting scheme, you’ve made the right choice! Colocasias love being in moist soil, which means you can use them to make a feature out of a tricky area of damp or boggy ground. They will also thrive in an ordinary border and containers too, as long as it doesn’t become too dry in summer. These versatile tropical plants are happy in sun or shade, which makes them suitable for growing in virtually any part of the garden. Whilst they grow a little quicker in sun, they maintain a fresher, more vibrant leaf colour in shade.
How to plant Colocasia
Colocasias are tender tropical bulbs and need warm conditions to thrive. Therefore, it’s important to start them off in individual pots indoors, preferably in a warm bright room, a conservatory or heated greenhouse at consistent temperatures of 17-25°C. They should be planted with the top of the bulb exposed and the ‘rings’ or papery layers facing upwards. They can take a while to sprout but when provided with the recommended temperatures, they usually wake up around 8-12 weeks after planting.
Once you’ve planted your bulbs, give them a little water regularly to get them started, but not too much at first as they may rot if too wet while still dormant.
When they have sprouted and outdoor temperatures are fairly consistently at 17-25°C or above (usually around May or June), Colocasia can be transplanted outdoors into patio pots or borders in rich, moist soil in sun or light shade.
— Plant your Colocasia bulbs in individual pots indoors during spring. Start them off in a location which is consistently around 17-25°C such as a windowsill, conservatory or heated greenhouse.
— Plant the bulbs shallowly with the top of the bulb level with the soil surface. The ‘rings’ or papery layers should be facing upwards.
— Water sparingly until the shoots emerge as Colocasia can be prone to rotting if the soil’s too wet while dormant.
— After the bulbs have sprouted and when outdoor temperatures remain consistently around 17-25°C or above, Colocasia can be transplanted outside.
— Once sprouted, plant outside in borders or containers in a sunny or lightly shaded position in a rich, reliably moist soil.
— When they are ready to transplant outside, space the plants 25-35cm apart from each other.
— Water-in after planting and keep well hydrated throughout the season.
Growing Colocasia in pots
Colocasia bulbs grow happily in pots. They can grow to be quite large over the summer, so it’s best to choose a sturdy container which won’t topple over with the weight of the plant. We recommend a container which is around 30-40cm (12-14in) in diameter. For Colocasia, choose a loam-free compost to fill your pot - a good quality multipurpose compost is ideal. If growing Alocasia, choose a soil-based compost. These bulbs like a moist soil, so to save water it is worth reducing drainage by putting a dish underneath your pot. Water your plant whenever the soil surface starts to look dry.
Colocasia as house plants
Tropical Colocasia and Alocasia make impressive house plants, their tall, upright stems and large leaves with intense colouring are a statement feature in the home or office. You’ll need a good space for them to thrive, close to a window or patio doors. Reaching a height of up to 1.5m, they’re best positioned on the floor or a low plant stand.
Colocasia plants grown indoors require regular watering. Top up their water whenever the surface of the soil starts to look dry. They look great in a large terracotta pot, around 30-40cm (12-14in) in diameter, or positioned inside a waterproof indoor plant container. Tropical bulbs love warm, humid conditions which you can mimic by misting with water from time to time. Colocasia die back in the autumn and become dormant. At this point, remove the old foliage and move the container to a cool but frost free place for winter. There is no need to water it while dormant.
Caring for Colocasia
Throughout the season, Colocasia require very little in terms of maintenance. Regular watering is key, then any damaged or tatty leaves can be removed if and when needed. Watering your plants in the evening avoids the risk of scorch marks developing on the beautiful leaves, it also gives the plants all night to absorb plenty of moisture.
These tropical bulbs will not tolerate frost, so if you would like to keep the bulbs for next year they should be moved to a frost free place in autumn. Container-grown Colocasias can simply be moved into a shed or cool greenhouse for winter. Once the foliage starts to die back, snip it off and let the bulbs remain dormant in their pots. Those which are growing in the ground should be carefully dug up and stored in trays or pots surrounded by a loose compost. If you have an Alocasia, it can remain evergreen if kept at room temperature so you can bring it in and enjoy it as a houseplant for the winter months.
With such striking leaves in summer, you can really get creative with Colocasia combinations. These fantastic foliage plants look great with vibrant flowers – for a tropical theme, try pairing them with zesty, long-flowering plants like dahlias and begonias. Other tropical bulbs like Bessera and Gloriosa will also work well to heighten any exotic, leafy display. If you’re growing it as a marginal pond plant, try a chic combination with white-flowered Calla aethiopica.