Caladiums are tropical perennials that have almost unparalleled foliage and make showy houseplants. They can also be grown outdoors, but unless you live in zones 9 to 10, you should plan to grow them as annuals, or dig up the plants’ tubers at the end of the growing season and store them for winter.
Caladiums are seasonal plants even in the tropics, where gardeners plant them in the spring and summer months when they’ll thrive in the heat and humidity. When grown indoors, they do best with lots of heat, bright but indirect light and plenty of humidity. Even under the best conditions, caladium foliage lasts only a few months before the leaves start to die back and the plant goes dormant again. This is okay—they’re supposed to do that.
Many gardeners use masses of these striking plants as summer accents and conversation pieces. When the plants die back, you can save the tubers in a bag and replant them next year for another show.
Caladiums are grown for their foliage, but they do have flowers, which start in the form of spathes, or spikes. Cut off any spathe as soon as it appears to ensure all of the plant’s energy is used for its gorgeous leaves.
Caladium plants prefer indirect light or moderate shade indoors. The narrower the leaves, the greater the sun they can withstand. Growing them outdoors in containers gives you more control over light conditions. In some climates, container plants can be grown in full sun, with careful monitoring. When growing them in a garden, give them partial shade to full shade; full sun scorches their leaves.
Plant caladium in a rich, well-drained potting mix, such as a damp mix of soil and peat. Garden soil should be similarly rich and well-drained. The ideal soil pH is slightly acidic, at 5.5 to 6.2.
When leaves appear on the plant, water as needed to keep the soil evenly moist. Never let the plant dry out. Stop watering the plant when the leaves start to die back. Resume watering when the leaves reappear next season.
Fertilize the plant weekly during the growing season with liquid fertilizer or use slow-release pellets.
Temperature & Humidity
The warmer, the better, for caladium houseplants. Aim for 70 degrees Fahrenheit, if possible, as that is the temperature at which tubers begin to grow. Keep the humidity as high as is practical. When planting outdoors, you can transplant potted tubers (or, better yet, simply transfer them in peat pots) after the last frost date for your area. Plants grown this way should be started indoors four to six weeks prior to transplanting.
Toxicity of Caladium
All parts of the caladium plant are poisonous, both to people and animals. Use caution when you have caladiums around children or pets.
Symptoms of Poisoning
Ingesting the leaves can cause swelling, eye pain, diarrhea and vomiting in humans. Pets, including dogs, cats and horses, can suffer pain and swelling of the mouth, tongue and lips, excessive drooling, difficulty swallowing and vomiting (excluding horses).
Information courtesy of TheSpruce.com