Blog: Have big-leaved beauties, Colocasia, aka taro, on your patio!
Every year, I treat myself to something new and exotic to try and this season, I’ll be growing elephant ears in pots. You’ll find them listed as Colocasia in most specialist nurseries – mine is the ‘basic’ C. esculenta. It grows to 1.5m tall with huge 60cm, heart-shaped, deep green leaves, marbled with subtle purple blotches and dark veins, held on black stems.
It’s taro in its native tropical East Asia, where the tubers are a staple food; however, all parts of the plant are poisonous if uncooked and can irritate the skin. I have a couple of Alocasia too (giant taro), which are grown in the same way. The only difference is that their leaves point upwards, instead of drooping down.
Growing Elephant Ears in pots – easier to care for
I’ve chosen pots over direct planting because I can control their needs more easily, move them if necessary, and it’s far easier to bring them indoors in winter. They’re not the easiest plants to grow, thriving in a warm, humid environment in full sun or partial shade. Colocasia are very thirsty and greedy, so they need plenty of water, rich soil and a sheltered site – our sunken seating area should be ideal.
As this is a new plant for me, I’ve scoured the web for growing information – sadly, much of it is conflicting. However, I hope I’ve weeded out the what from the chaff and they end up a success.
Start indoors or plant straight outside?
The best advice I found was from Harvesting Heirloom LLC on YouTube. Described as very slow starters, it’s worth planting them asap indoors, in a heated greenhouse or a conservatory to give them a chance to build up steam. Leave it until after the last frost (late May/early June here), and they will be a waste of time. You start off each tuber in a temporary pot (mine are in 5 litre/22.5cm pots). Once through, keep potting on until they’re in a 36cm container (9.2 litres) or even bigger.
Which way up do you plant the tubers?
Colocasia’s tubers look like battered cricket balls with ring markings. Plant ‘the bullseye’ upwards (easy to spot if there’s a pointed tip or a shoot there). If in any doubt as to which way is up, plant it on its side!
Do you cover tubers or leave the tip sticking out?
Hmm – a real split of opinion here. Many sites advise leaving the tip of the tuber sticking out, planting 2.5cm deep or even 10cm deep! I went for the latter, as the plants are top-heavy in pots. Even gentle winds will make the foliage move around, loosening the roots and blowing the pot over.
Growing Elephant Ears in pots – what type of soil to use?
I went for a good-quality peat-free multipurpose compost. The RHS advises a neutral or slightly acidic, poorly drained soil. When I pot them on, I’m going to add in a bit of ericaceous compost and some water-retaining gel crystals to give them (and me) a helping hand.
How to feed Colocasia?
I told you they were greedy! I added 25g per pot of slow-release fertiliser pellets to each pot. As they grow, they will need high-nitrogen fertiliser, plus an addition of well-rotted manure or pelleted chicken manure.
How to water Colocasias
Once potted up, water thoroughly. Colocasia prefers slightly wet or boggy conditions for growth, but for now, ensure that the soil is well watered and not saturated. Water regularly when you can see shoots, and don’t let the compost dry out completely. I’ve found that after a couple of years of experience, they are very happy plonked in a fabric pot in a Belfast sink outdoors for summer. I’ve also had success with ordinary pots placed in a trug full of water or in trays filled with water.
Growing Elephant Ears in pots – how to overwinter
Colocasia are tender and can’t stand frost (RHS hardiness rating H1B – can be kept outside in summer). When the temperature drops consistently below 10-15°C, move potted plants into a greenhouse or conservatory for winter. You can even keep them indoors as a houseplant – if kept over 21°C, they will keep their leaves. They will lose their leaves at lower temperatures, but as long as they are kept frost-free, they will grow new leaves the following year.
Despite loving wet feet during the growing period, when temperatures drop, keep them on the dry side. They will often die back to the tuber and go dormant. Simply start them back into growth by repotting and watering the next spring.
