Lance-leaved caladiums attach their leaf stem on the edge of the leaf blade, such as the Lance Whorton variety on the left, while fancy-leaved caladium leaf stems are attached within the leaf blade as seen on the Tapestry variety on the right. (Photo by Yan Chen, LSU AgCenter)

Sangria is a new lance-leaved caladium variety released in 2014. It has an orange hue on mature leaves. (Photo by Yan Chen, LSU AgCenter)

Scarlet Flame is a new lance-leaved caladium with dark scarlet red patches on rose-red leaves circled with a dark green edge. Both Sangria and Scarlet Flame can take more sun than traditional fancy leaf caladiums. (Photo by Yan Chen, LSU AgCenter)

News Release Distributed 06/04/15

HAMMOND, La. – Caladiums are one of the most popular warm-season bedding plants among gardeners in the South because of their attractive foliage color and the ability to thrive in our summer heat and humidity. They are essentially pest- and disease-free and require very little maintenance, said LSU AgCenter researcher Yan Chen.

“Once planted at the right location, caladiums can provide colorful landscape plantings for people to enjoy throughout summer and early fall,” Chen said.

Caladiums can be grouped as fancy-leaved or lance-leaved, she said. The two groups have different genetic backgrounds and are distinctively different in their appearances and how much sun they can tolerant.

Fancy-leaved caladiums are about 2 feet tall and produce large round-ovate to triangular leaves with three main veins, and the leaf stem attaches within the leaf blade.

Fancy-leaved caladiums look best at locations with partial shade, which means about two to four hours of sun in the morning and filtered sun or shade for the afternoon, Chen said. They will show sun damage if planted in a location receiving more than four hours of full sun or a strong western afternoon sun.

Most commercial varieties are in the fancy-leaf group and are more familiar to gardeners, Chen said.

“Classic varieties such as Aaron, Candidium and White Queen are in this group and have been commonly used in our landscapes for many years,” she said. Some newer fancy-leaf varieties, such as those out of the University of Florida breeding program, performed well in caladium variety trials at the LSU AgCenter Hammond Research Station.

“Fancy-leaved varieties we recommend include Fire Chief (red), Carolyn Whorton and Florida Elise (pink), Florida Moonlight (white) and Tapestry (tri-color),” she said.

Although lance-leaved caladiums are relatively new on the market, they have been in demand because these varieties tolerate full-sun conditions much better than the fancy-leaved types.

“Plants in this group are also called dwarf caladium because they are more compact with smaller leaves and shorter leaf stems than fancy-leaved varieties,” Chen said. Leaves are thicker and sometime waxy compared with fancy-leaved varieties.

The leaf stem of lance-leaved varieties attaches at the edge of the leaf blade, and the tubers are also smaller and more branched, Chen said. Overall, lance-leaved varieties are more resilient to stresses such as wind and drought and can take six or more hours of full sun without sunburn damage.

“In a landscape full-sun trial at the Hammond Research Station, we found that foliage colors of this group are brightened up by sun, and plants can tolerant complete full-sun locations as long as they are well irrigated,” Chen said.

Under complete full-sun conditions, lance-leaved plants are shorter with more intense color than if they are under some shade, she said.

“Lance-leaved varieties that performed well in our trials include Red Ruffles, Florida Sweetheart, Hearts Delight, Scarlet Flame, Candyland, Lance Whorton, White Delight and White Wonder,” Chen said.

New caladium varieties are being evaluated year when they become available from breeding programs in Florida. “Varieties released from 2012 to 2014, including Hearts Delight, White Cap, Scarlet Flame and Sangria, can be seen in our shade gardens at the Hammond Research Station in addition to the other varieties recommended to Louisiana gardeners.”

Gardeners can buy caladium tubers in spring and container-grown plants from mid-to-late spring through summer. In Louisiana, it is best to plant caladiums in the second week of April through early May instead of in March because they grow best when soil temperature is warm, Chen said.

Caladiums grow better when planted in a raised bed with good drainage to prevent tuber rot. Proper bed preparation includes turning the soil in the area to be planted and then incorporating a 4-to-6-inch layer of organic matter such as pine bark and compost.

Fancy-leaved varieties can be spaced at a 12 to 18 inch apart, while lance-leaved varieties should be spaced 8 inches apart to provide immediate color in the landscape. “They will grow larger and more beautiful throughout the summer and have a peak performance in late summer to early fall,” Chen said.

To fertilize caladiums, an all-purpose fertilizer can be applied into the upper few inches of the soil according to label directions. A small amount of slow-release fertilizer can be placed around each tuber as it is planted into the bed.

The Hammond Research Station features recommended caladiums planted along the front of the property and in the shade gardens.

Rick Bogren