Caladiums, Caladium bicolor, are grown for their long-lasting, colorful foliage. Color combinations include various shades of red, pink, white, green, and yellow-green, with prominently colored midribs and contrasting margins. There are two basic types of caladium cultivars: fancy- and strap-leaved. Fancy-leaved types have large, heart-shaped or semi-heart-shaped leaves borne on long petioles. The strap- or lance-leaved types have smaller, narrower, thicker, elongated leaves on short petioles giving the plants a more compact habit. Strap-leaved caladiums produce more leaves per tuber than fancy-leaved caladiums. Fancy-leaved types range in height from 12 to 30 inches while most strap-leaved types are under a foot in height.

There are thousands of caladium cultivars to choose from. Some of the best performing cultivars are listed below.

Fancy-leaved Caladium Cultivars

Strap-leaved Caladium Cultivars

Nurseries and garden centers offer caladiums as potted plants or dormant tubers. Tubers are available in four different sizes based on diameter and are priced accordingly. Tuber sizes are classified as mammoth (3¹⁄₂ inches and up), jumbo (2¹⁄₂ to 3¹⁄₂ inches), No. 1 (1³⁄₄ to 2¹⁄₂ inches), and No. 2 (1¹⁄₄ to 1³⁄₄ inches). Large tubers have more leaf buds than smaller tubers and, therefore, make a larger foliage display.

Each caladium tuber has a large, central bud surrounded by several small buds. If the large, central bud is allowed to grow it will prevent the small buds from growing and producing leaves. Use the tip of a sharp knife to lift out the large, central bud, being careful not to injure any of the surrounding small buds. De-eyeing will stimulate the production of a greater number of, but slightly smaller, leaves.

Caladiums grow best in the partial shade of open, high-branched trees. They will perform reasonably well in full shade, but the color may not be as outstanding. Caladiums traditionally needed protection from full sun for best growth and color, but some of the newer cultivars tolerate exposure to full sun for a couple of hours daily. Most pink-leaved caladiums develop a brownish, scorched appearance when grown in sun.

Caladiums require warm, moist soil. A minimum soil temperature of 70°F is preferred. If planted too early in the spring, cool soil temperatures will cause tubers to rot before they sprout. Some gardeners prefer to start tubers indoors in moist peat moss or potting soil in containers such as a shallow flat or flower pot. Barely cover tubers with soil and place the container in a warm room with bright light. Tubers should be started indoors approximately four weeks before planting outdoors.

For best growth, plant caladiums in well-drained soil with a pH between 6.0 and 6.5. A 2- to 3-inch layer of pine bark mulch or compost should be incorporated into the soil to improve soil aeration, drainage, and organic matter content. Root and foliage growth will be limited unless the soil is well aerated. Also, incorporate a complete fertilizer such as 8-8-8 at a rate of 1 to 2 lb per 100 square feet of bed area (2 tablespoons per square foot). Plant tubers 2 inches deep and 8 inches apart for small tubers and 12 inches apart for large tubers. Both roots and shoots emerge from the top of the tuber; place the knobby side up.

Mulch with a 2- to 3-inch layer of organic material to conserve moisture and keep the soil cool. Soil temperatures over 85°F can result in leaves with more green color and less of the highly prized, brilliant colors. High levels of nitrogen fertilization can produce the same effect. Caladiums are heavy feeders of potash and phosphorus and must have ample moisture and summer feeding of fertilizer in order to produce good tubers for the next growing season. Apply 1 tablespoon of 5-10-10 fertilizer per square foot every 4 to 6 weeks during the growing season. For individual plants, use a heaping tablespoonful; for plants grown in containers, use a level teaspoon per pot. Do not allow fertilizer to contact the leaves. Water thoroughly after fertilization to prevent fertilizer burn. Caladiums are not drought tolerant and should be watered on a regular basis.

Sometimes plants will produce a bloom which is similar to a Jack-in-the-Pulpit or calla lily. Most home gardeners prefer to remove the bloom since it takes away energy from the foliage and reduces tuber size.

Tuber rot -- Tubers may decay in storage or during the growing season. Several bacteria or fungal organisms cause tuber rot. Bacteria cause a soft, slimy decay, while fungi cause a dry, chalky rot. To reduce the potential of tuber rot, select disease-free tubers for planting and store tubers properly to avoid high humidity and cool temperatures. Never store caladium tubers in the refrigerator. Tubers purchased in early spring, before ideal planting time, should be held at room temperature. Follow soil and planting procedures mentioned previously.

Leaf spot -- An anthracnose fungus can cause the lower leaves to develop light tan to brown spots. Generally, the disease is not severe enough to warrant chemical control. Remove and destroy diseased leaves as they appear.

Leaf burn -- Burning of older leaf margins and scorching of leaves usually are the result of foliar application of fertilizer, excess sunlight, or a lack of water. Cultivars with thin, translucent leaves are especially prone to scorch when under drought stress or when phosphorus or potassium are deficient. The older foliage is especially prone to drought damage.

Caladiums can be treated as annuals and left in the garden to be killed by cold weather. However, it is possible to save caladium tubers for planting again the following year. In the fall with the onset of cool nights, the leaves will begin to fade and droop. Before the leaves have lost all color and before soil temperatures drop below 55°F, dig the tubers that are to be saved, retaining the foliage, and sort them by color or cultivar. Spread them out in an area protected from rain and cold, and allow them to dry for a week. Do not place in full sun. After leaves have dried, cut them from the tubers. Store the tubers in mesh orange or onion bags, or pack lightly in dry sphagnum moss and store them where the temperature will not fall below 60°F.