by Jerry Parsons, Ph.D.
Horticulture Specialist, Texas Agricultural Extension Service in San Antonio
There is no caladium-testing program in this area but the Dallas Botanical Center has been conducting tests of about 100 varieties for nearly a decade. Results of their extensive testing program should give us some idea of the true winners in the caladium kingdom.
"Fancy Leaf" caladiums are the most useful in home landscapes. Derived from Caladium bicolor, a Brazilian species, the broad heart-shaped foliage usually is a riot of pink, red, white and green splotches. Some varieties are solid red or white with deep-green trim along veins and outer edges. The pinkish flowers are short-lived, but leaves remain fresh and vibrant all summer long.
"Lance Leaf" caladiums (derived from Caladium picturantum) are smaller and more compact. Their pretty, ruffle-edged foliage seems tailor-made for window boxes and patio planters. These plants also thrive indoors near bright windows.
Caladiums are closely related to the popular and almost indestructible philodendron --and are just as resilient despite their delicate appearance. In fact, few garden plants are easier to grow.
Foliage sprouts from bulb-like tubers, which are available during spring and early summer, as are caladium seedlings and full-size plants. Gardeners have dozens of multi-colored varieties to choose from. For economy --especially when mass planting --go with tubers. Delay planting until all danger of frost has passed and soil begins to warm. (That's now folks!) Caladiums tolerate most soils but perform best in earth that is richly organic. If soil is sandy or heavy with clay, spade in peat moss or compost at planting time.
Place tubers bud side up in furrows or individual holes 9 to 15 inches apart. Cover with 3 inches of soil, tamping firmly around each tuber to eliminate air pockets. Water immediately. Thereafter, moisten only when the soil surface becomes dry. A 2 to 3-inch mulch of wood chips, ground bark or other organic material helps retain soil moisture and discourages weeds.
Want to try something different on your caladium bulbs this year? Try cutting their eyes out! It will result in more leaves and remember, leaves of brightly colored foliage is what caladiums are all about. Just take a sharp spoon or knife and scoop or cut off the apparent eyes or buds on the tubers before planting. Such a procedure delays emergence for a few days but it causes the tuber to sprout more dormant buds rather than the fewer main buds. The result is an abundance of foliage rather than a few shoots. Try some and leave some -see which gives the better results.
Depending on soil conditions, the first leaves break soil 3 to 6 weeks after planting, setting shaded areas aglow. Keep the caladiums glowing by applying fertilizer around emerging plants. A good rule of thumb is 2 pounds of 19-5-9 per 100 square feet of planting bed. Re-apply monthly. As plants fill out, a liquid fertilizer drench may be more convenient. Standard houseplant food suffices for container-grown caladiums.
So which are the best caladium varieties? I will list the variety name, the 4-year average survival period (in weeks) and the 4-year average height (in inches).
The best of the standard, "fancy leaf" types are Candidum (21) (19), Carolyn Whorton (23) (22), Fire Chief (21) (20), Florida Beauty (22) (24), Galaxy (24) (21), Miss Chicago (21) (20), Pink Shell (21) (15), White Christmas (21) (19), White Queen (22) (21).
The best of the strap or "lance leaf" types are Caloosahatchie (23) (14), Candidum Jr. (21) (14), White Wing (22) (18), Pink Gem (24) (23).
All of the above varieties were chosen because of their ability to survive for 21 weeks or more. If you can spare a week or two, the following are the most commonly sold varieties and their endurance (in weeks): Aaron (20), Blaze (18), Fannie Munson (19), Festiva (20), Freida Hemple (18), John Peed (18), June Bride (19), Lord Derby (18), Pink Beauty (20), Pink Cloud (20), Red Flash (18), Rose Bud (18).
There are other superior varieties which should be sold but are not commonly available. They include the "fancy leaf" varieties Jubilee (25) (21), Pink Lady (22) (18) and Sea Shell (23) (13). Other superior strap or "lance leaf" types include Jackie Suthers (26) (17), Mumbo (23) (16), Pink Symphony (23) (15), Red Frill (21) (11), and Lady of Fatima (24) (14).
If you purchase one of these superior varieties and want to try to save the tubers for planting next spring, dig them in the fall and store them for spring replanting. When foliage begins to yellow and daytime temperatures drop and remain below 60 degrees F, the time is right to dig caladium tubers. Air dry tubers for several days on a flat sunny surface. Allow leaves to fall off by themselves. This way they keep supplying tubers with needed nutrients.
Store tubers in dry peat moss or dry sand. Choose a well ventilated spot where temperatures ideally remain between 70 and 75 degrees F. Do not refrigerate. Within 8 weeks new growth may sprout, indicating tubers are healthy and prepared in advance for spring garden action.