Growing Elephant Ears; Colocasia and Alocasia

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Robert Pavlis

This is a great tropical looking plant, that is easy to grow, and makes a big statement especially in colder climates where such large growth is hard to come by. And even better, it is so easy to overwinter.

Growing Elephant Ears; Colocasia and Alocasia, by Robert Pavlis
Growing Elephant Ears; Colocasia, by Robert Pavlis

What are Elephant Ears?

The term elephant ears is used for a variety of plants in the genus Colocasia and Alocasia. Both genera contain several species, but in the gardening world everyone seems to clump them together and, because of their leaf shape, call them elephant ears.

Alocasia macrorrhiza, leaves pointing up
Alocasia macrorrhiza, leaves pointing up

Taro is the name used for a root/tuber that is commonly sold for food and it is a Colocasia. You can buy taro in a grocery store and grow it.

Elephant ears have also been hybridized to produce leaves of various sizes and colors in the green, blue, black range. They do bloom with an arum-like flower, but the plants are grown mostly for the leaves.

Soil Science for Gardeners book by Robert Pavlis

Colocasia vs Alocasia

There are botanical differences between the two, but one way to tell them apart is that Colocasia has leaves with the tips pointing down and most Alocasia have leaves pointing up.

Elephant Ear Bulb Myth

People talk about their bulb, or tuber, but the growth is actually a corm, which is a swollen stem. Crocus, gladioli and cyclamen are also grown from corms, not bulbs.

YouTube video

Planting Elephant Ears

Elephant ear corm/bulb, by Robert Pavlis
Elephant ear corm, by Robert Pavlis

The best way to grow these plants is to buy the corms and plant them them in moist soil. Some people grow them in water, but not all varieties do well that way. The Alocasias don’t like wet roots. The Colocasia can be grown partially submersed in water, but they can also rot that way. It is best to grow them in soil.

Plant them so that the top of the corm is about 1″ below the surface.

The plant corm in the picture was grown with about 5″ of soil above it, and it formed a new corm higher up. The bottom ball (darker area) is the old corm, and the top one grew last year. Corms and some true bulbs do this if they don’t like the planting depth – they change it.

When to Plant:

They are not frost hardy and don’t grow much in cold soil. Wait until the soil warms up and there is no danger of frost. In zones 9-11, they can be in the ground all year.

Planting orientation

Plant with the point facing up. In some cases there will be no pointy end, so it is OK to just plant the corm on its side or even upside down. Plants can sense gravity and know which way to grow.

Moisture:

They like a lot of moisture. If possible plant in a bog that does not have standing water, but they will grow in normal garden soil moisture. More moisture will give you larger leaves.

Growing Elephant Ears; Colocasia and Alocasia, in Aspen Grove Gardens, by Robert Pavlis
Growing Elephant Ears; Colocasia, in Aspen Grove Gardens, by Robert Pavlis

Sun:

This really depends on your climate and the amount of moisture in the soil. In cooler, wet areas they can grow in full sun. My plant grew well in a bog in full sun (zone 5). In warmer climates they appreciate some shade.

Green cultivars can take higher light. Dark colored ones prefer some shade.

Hardiness:

They are hardy in US zones 8-11. Some cultivars are also hardy in zone 7 with some protection.

Fertilizer:

I normally do not recommend fertilizer for any garden plants unless you know you have a nutrient deficiency, but I will make an exception in this case. A bit of fertilizer will produce larger leaves which are more dramatic. Elephant ears are heavy feeders but be careful you don’t overdo it. To much fertilizer can lead to browning of the leaf tips.

Overwintering Elephant Ears

In fall, before a hard freeze hits the plant, cut all of the leaves off, dig up the corm, remove old roots and store it dry in a cool place like a fruit cellar. You do not need to add peat moss or wood shaving to keep it from drying out. These are very tough corms.

They only grow when it is warm, and a cool place keeps them in hibernation until you are ready to plant them again.

I have created a video to show you how to prepare and store them for winter.

YouTube video

Getting An Early Start

Elephant ears do not grow in cool soil which is a bit of an issue in colder climates since we have such a short summer. They grow just fine and make a large plant even if you plant the corms outside. However, you can extend the growing season to produce larger plants, by starting them early.

Start six to eight weeks before your last frost date. Pot up the corm, water it and move it to a warmer location. It will take several weeks before you see any leaves growing. At that point give it light.

Once the frost is out of the ground you can move it outside to provide more light and condition it to the wind. Then plant it once the soil is warm (18C or 65F).

YouTube video

If the above video does not play try this link:ย https://youtu.be/FHIrfB5LK-Q

Growing a Monster Elephant Ear

I love large leafed plants. So my goal is to grow the largest elephant ear that I can. Here are some tricks that help.

  • Keep well watered – drying slows down growth
  • Fertilize
  • Buy large cultivars, like “Thailand Giant” and “Laosy Giant”
  • Start early indoors

Enjoy your elephant ears.

 

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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

9 thoughts on “Growing Elephant Ears; Colocasia and Alocasia”

  1. Loved all of the pointers, but I have a question. I had alacasia and colocasia growing together. At the end of the season the alacasia took over the bed which is great since I favor them. Now I only see the colocasia coming up. I also gave a couple os the alacasia to my sister and hers came up as a colocasia. I was very careful to gave her a bulb that was attached to the right one! Can they cross breed?lgwa

    Reply
    • To cross breed you would needed flowers on both plants, and seed produced. They don’t cross breed vegetatively.

      Reply
  2. I Love Elephant Ears. Before I moved from Pensacola, FL to Springer, OK I dug up some “wild growing” Ears. I planted them on the North side of my house (I didn’t want them to burn up). The heat was very intense, so I Watered them twice a day. I fed them Miracle-Gro liquid fertilizer. They grew to a whopping 7′ tall. When I moved to Chicagoland I left them in Okee. I currently have 3 different varieties (and looking for more) that are in large pots. Because of the “tundra” type winters here, I bring them in and they grow great. Thank you for all your info. I look for as much as I can get.

    Reply
  3. I bought an Colocasia Taro Elephant Ear a little while ago. I keep it in doors because I thought I could put it outside but I believe it got cold frost on one leaf. So I brought it back indoors and now its producing and looking great. I would like to know why a couple of the leaves point down and the others up. Also, how do I know when or if to put any elephant ears outside? I have 3 different kinds. But I don’t want to ruin them. Any help on this would be greatly appreciated.

    Reply
  4. Enjoyed the video. Your explanation about growing and caring for these plants was straightforward and clear. I think I might give one a try this season.

    Reply

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