Colocasia esculenta 'Fontanesii'

Its common name, black stem elephant ear, may say it has a black stem, but it really is a dark purple hue, so dark it appears to be black. Colocasias are often called elephant ears; however, when I lived in Hawaii we knew these evergreen, big leaf plants as taro. Grown as a vegetable food, taro must be cooked or steeped in water to remove the toxic calcium oxalate before it is eaten. For many people, including myself, unless they ate poi (made from the taro plant) as a staple food when they were children, they don’t care for the bland, starchy taste.

These bulbs are hardy in USDA zones 8-11, yet Sunset’s Western Garden book does not rate them hardy in the maritime Northwest. However, a local nursery owner advised me to use a two-year-old plant, grow in humus rich soil and mulch heavily, and see them suvive in Sunset zone 5.  My plants will be three years old this next season; I will experiment with this plant and see how it does in the garden. In our climate, the plant will die back to the ground over winter; it won’t be evergreen like it is in Hawaii. It may take a few winters before I know if it is hardy enough to survive. In the meantime, while my experiment waits for an unusually cold winter, I will grow more in containers and winter them over in the greenhouse.

The flower gives it away that colocasias are in the aroid family, Araceae. The yellow flower looks similar to many in the family, such as our much maligned Northwest native skunk cabbage, Lysichiton americanus. Unlike our native son, this colocasia flower has the scent of papaya, according to Tony Avent of Plant Delights Nursery in North Carolina. I did not catch a fragrance on my own plant, but then I might have been too nervous to sniff around a skunk-cabbage-like flower. Next time it flowers, I will gingerly inhale its odor, just in case Avent is pulling our collective legs about the reward of papayas after a deep inhale.

To grow the tallest stems and larger leaves, give them constant moisture, humus rich soil and lightly fertilize once a month. You can grow these bulbs in containers, or plant them in a pot and sink them into a water garden. They add a tropical flair wherever you plant them. The plants send out runners, with a small leaf on the end, that appears to be stems flopped over. Use the runners to propagate more plants by allowing the runner to coil around the inside of the pot until fully ripe. Divide the suckers out and plant on in a one gallon pot and overwinter in a sunny, frost-free space. Slowly acclimate outdoors after last frost.

 

Comments

[Flora]

These babies are wonderful, I never saw them bloom before and they look like skunk cabbages. Thanks for the great info!

[Chris Porter]

If one ages/ferment poi for a while, it gets a nice sharp-musty taste. The taste of fresh poi isn't nearly as interesting, yet it seems to be the only kind served to tourists.

[Debbie TT]

Hi Chris, I never tried fermented poi, one taste of poi, was enough for me. I take it you lived/live there?