Xanthosoma are not typically thought of as houseplants—in tropical countries, they are farmed for their starchy tubers, and almost everywhere else they are the collectors' plants known as elephant ears and grown in botanical gardens and greenhouses. But with the increasing availability of rare plants, Xanthosoma are worth a long, hard look. These plants feature sometimes very large arrow-shaped leaves, as well as some of the most striking, elegant leaves in the plant kingdom. With their expanses of green, their graceful draping, and their lovely form, Xanthosoma are the essence of the rainforest.
A herbaceous perennial, Xanthosoma sagittifolium has a corm or main underground stem in the form of a rhizome from which swollen secondary shoots, or cormels, sprout. The spadix (a spike of minute flowers) is cylindrical, with female flowers on the lower portion, male flowers on the upper portion and sterile flowers in the middle portion. The growth cycle lasts from nine to 11 months: during the first six months the corms and leaves develop; in the last four months, the foliage remains stable and, when it begins to dry, the plants are ready for the cormels to be harvested.
Xanthosoma is native to tropical America. The leaves are edible, but they (and all parts of the plant) contain needle-like crystals of calcium oxalate which are a skin irritant, so they must be cooked first.
Growing Conditions for Elephant Ears (Xanthosoma)
These are tropical plants, so the conditions must be right for them to grow:
- Light: Bright light but no direct sun. Some can handle shade.
- Water: Throughout growing season, water and mist frequently. Many Xanthosoma will die back to tubers in the winter, but don't let the tuber completely dry out.
- Temperature: Prefers warm and humid conditions. Keep above 60ºF if possible.
- Soil: Rich, well-drained potting mix.
- Fertilizer: Heavy feeders. Feed throughout growing season with liquid or powder fertilizer.
Like many tuberous plants, Xanthosoma can often manage fairly well in the same pot for several consecutive seasons, sending up a new flush of growth each season. If, however, large and spectacular growth is your goal, repot the rhizome into a fresh pot at the beginning of each growing season. Be aware that some species can be very large and plan accordingly.
There are about 50 species of Xanthosoma throughout the tropical Americas. Some of the more beautiful or striking ones include:
- X. Lindenii. Perhaps one of the most beautiful of all foliage plants, with 20-inch green leaves that feature silvery, almost white ribbing.
- X. Sagittifolium. A true conservatory specimen, with unmarked green leaves that can easily achieve a length of 4 feet, rising on 5-foot stems. Feed and water heavily for maximum growth.
- X. 'Key Lime Zinger'. A rather popular, lime-green landscape plant with large, showy leaves that can thrive indoors.
Xanthosoma belong to the Arum (or Araceae) family of plants, sometimes called aroids. This family includes philodendron, colocasia, caladium, alocasia and other very tropical foliage plants. Like these other aroids, Xanthosoma thrive in an environment of high humidity, copious water and food, and elevated temperatures. They are understory plants, or they sometimes grow at the edges of water, so they are not suited to direct harsh sunlight. Pests include spider mites and mealy bugs, which are both more likely to attack unhealthy plants.