You'll undoubtedly have heard of elephant ears if you're a tropical houseplant fanatic. This is the name given to many plants within the Arum (or Araceae) family that stand out for their impressive heart or arrow-shaped foliage. Alongside more well-known aroids like the Philodendron, Alocasia and Colocasia, there is also the Xanthosoma genus (pronounced zanth-oh-So-mah).
While certain plants in this genus are better known for their starchy tubers that people harvest as a food source in tropical countries, there is a growing demand for some species as rare, exotic-looking houseplants. If you want to add to your verdant indoor jungle, don't rule out these elegant, lush, large-leafed herbaceous perennials with prominent venation. You can also grow them outdoors in warm, frost-free regions, but be aware of their fast-growing, invasive tendencies. Most species can be planted in the spring when the danger of cold snaps has passed.
While some Xanthosama are edible once cooked, keep them away from curious kids and pets. All uncooked parts of the plant are toxic.
|Common Name||Elephant's ear, American Taro|
|Botanical Name||Xanthosoma spp.|
|Plant Type||Perennial, Herbaceous|
|Mature Size||Up to 8 ft. tall|
|Sun Exposure||Partial, Shade|
|Soil Type||Moist but Well-drained|
|Soil pH||Acidic, Neutral|
|Flower Color||Greenish White|
|Hardiness Zones||8-13 (USDA) depends on species|
|Native Area||Central and South America|
|Toxicity||Toxic to people and pets|
Like many other aroids, Xanthosoma make great plants for bathrooms. But they aren't always a good choice for beginners because of their specific needs. Most thrive in warm, high humidity environments, appreciate copious amounts of water, and are heavy feeders (although requirements vary by species). As you would expect of understory plants that grow on the jungle floor or at the edges of water in their native habitat, they aren't direct sun lovers.
Unless you live in a region with year-round balmy temperatures, you'll need to plant new Xanthosoma away from strong winds every year, overwinter them indoors, or keep them as a permanent addition in your houseplant collection.
Some Xanthosoma species grown in North America are classed as invasive plants in hotter regions. One of the most common is Xanthosoma sagittifolium, and this is categorized as invasive in Florida and the surrounds.
Typical aroids, Xanthosoma usually appreciate plenty of bright, indirect light. Some can handle shade, but they rarely thrive in direct afternoon sun, which scorches the stunning foliage. Rotate the pot weekly to encourage even growth.
Most Xanthosoma need a well-drained, moist, humus-rich soil or potting mix to encourage the healthy growth of their stunning foliage. Avoid dense clays (they don't tolerate waterlogged soils), very loose, dry sands, and alkaline soils.
If you're making up your own mixture, try two parts sphagnum moss, two parts coarse sand or perlite, and one part all-purpose potting soil. Throwing in some decomposed garden leaves won't hurt either. Make sure the pot has decent drainage holes.
To keep the prized foliage of your Xanthosoma looking verdant and healthy, it will need regular and thorough watering. During the hot growing season, this could be two or three times a week and still once every week or two in the winter.
These plants don't like being waterlogged, so allow the top inch or so of the soil to dry out a little between waterings, especially if the weather isn't too warm. The key is consistently moist but not wet conditions to avoid root rot.
If you occasionally forget to water your Xanthosoma, it usually isn't a cause for panic. Even if the foliage dies back, the corms (small, chunky stems containing nutrients) will continue to grow. But prolonged dryness is a no-no.
Temperature and Humidity
Exact requirements vary depending on the individual species, but generally, tropical Xanthosoma do best with temperatures between 60 and 80 degrees Fahrenheit. To appreciate the fullest foliage, strive for humidity levels of 60% or above. Drier air can be tolerated (especially if soil moisture levels are kept consistent), but using a humidifier, a pebble tray filled with water, and keeping plants away from air conditioning and heating vents can help.
Most Xanthosoma, with their large, thick leaves, are heavy feeders. Feed these plants every two to three weeks during the growing season with a weak liquid fertilizer or organic fish emulsion. This promotes growth and retains mature, healthy foliage for longer. During the winter, fertilizing just a couple of times is usually enough.
Types of Xanthosoma
There are over 70 species of Xanthosoma, but only a small proportion of these are available to cultivate as houseplants. Of those obtainable commercially, most are rare and difficult to source. Some of the species and cultivars more readily available or in particularly high demand include:
- Xanthosoma sagittifolium: One of the most readily available, fast-growing species, with grand dark green foliage that can grow up to 4 feet in length in the right conditions.
- Xanthosoma lindenii: Also known as Angel Wings, if you can get your hands on one of these babies, you'll be rewarded with striking foliage with a silvery hue and white venation. Growing up to 3 feet tall, when mature, this makes for a standout bathroom floor plant.
- Xanthosoma 'Lime Zinger': Very on-trend because of the unusual chartreuse to lime-green foliage, this plant can grow to 3 feet tall and does well in home environments.
You won't have to get the pruning shears out regularly if you own a Xanthosoma. It's just a case of removing old, unhealthy leaves to direct the energy to the healthy foliage.
Xanthosoma are typically propagated via division of the tubers, pups, or rhizomes of mature, healthy plants during spring. Make sure you select a healthy cutting with a sterile knife. Keep the cutting moist, warm, and in a well-draining potting mix for best success.
Common Problems With Xanthosoma
Xanthosoma aren't immune to problems. However, you can often remedy issues by making simple changes in light, moisture, or temperature. Look out for the following:
This is a common sign that you aren't watering your Xanthosoma enough. But be careful not to waterlog your plant.
Leaves Turning Yellow
Conversely, the first sign that you might be too conservative with your watering schedule is the yellowing of seemingly healthy foliage.
This can signal you're not getting the right balance with fertilization, exposing your plant to too much direct sunlight, too little water, or overly dry air.
How fast do Xanthosoma grow?
Most Xanthosoma species are relatively fast-growing, and mature plants can develop in as little as 14 weeks, producing lush foliage from 6 months onwards.
What is the difference between Xanthosoma and Caladium?
Caladium, with their lush, showy foliage, are often confused with Xanthosoma species. But Caladiums tend to be kept drier and dormant outside of spring and summer.
Do Xanthosoma have attractive flowers?
Don't grow Xanthosoma expecting showy flowers. They rarely bloom in home environments, and, even when they do, they aren't all that attractive.
‘Elephant Ear’. Pet Poison Helpline
Arrowleaf Elephant’s Ear: Xanthosoma Sagittifolium (Arales: Araceae): Invasive Plant Atlas of the United States.