Colored Callas Make White Pale by Comparison

If classic white Calla lilies seem not quite lively enough for your garden, you might want to try some of the new hybrids that pack a color wallop. Hybridizers are introducing small versions of the flower in hot pink, brilliant yellow, apricot and lavender.

Although colored callas are in the same family as the common whites, they’re actually a different species with different growing requirements. That’s why some gardeners report problems with the colored callas, which do better grown in containers than in the ground.

Although there are approximately 80 varieties of colored callas, just 15 are commercially available. But new varieties are appearing almost yearly.

Gloria Large, a garden enthusiast in Huntington Beach, included a dozen colored callas in her garden last year. Her effort to grow them in the ground was unsuccessful; when she switched to containers they thrived.

Large is an avid amateur flower arranger, so her garden serves double duty--producing color and foliage for outdoor enjoyment and home-grown material for her floral arrangements.

“These smaller callas brighten up a garden or patio and as cut flowers last a long time in flower arrangements,” she said. “I also use the white callas, but since they’re so large, they need to be in big arrangements suitable for large spaces.”

Richard Foster of Fullerton is also a fancier of the colored callas. He’s recently turned his back yard into a garden filled with drought-tolerant plants. He uses the callas in containers to add splashes of color around the patio.

“They look terrific,” he said.

Although the colored callas seem like newcomers to the nurseries, hybridizers have been working on them for decades.

“During the past 80 years, hybridizers have been developing these varieties by crossing species,” said Tom Lukens, president of Golden State Bulb growers in Watsonville. The firm claims the title of world’s largest producer of colored callas--more than 3.5 million annually sold as rhizomes and seed to wholesale companies throughout North America, Japan and Europe.

New Zealand is also a major exporter of colored callas, with the government sponsoring research into tissue culture and breeding.

Callas are popularly termed lilies, but they’re not. The botanical name is Zantedeschia. The white variety is Zantedeschia aethiopica and, in its native South Africa, prefers very damp soil, growing even in bogs. These plants are tall and aggressive spreaders in the right growing conditions.

The new colored callas are being developed from several species of Zantedeschia, also native to South Africa. But these species thrive in dry, sandy soil. Z. elliottiana is the Golden Calla; Z. albomaculata is the Spotted Calla, with flowers of creamy yellow or white with purplish crimson blotches at their base. Their leaves are spotted with white. Z. rehmannii is the source of red or pink callas, and hybrids include hues of lavender, purple, buff or orange.

Technically what is thought of as the flowers on callas are modified leaves, termed spathes. The true flower is the insignificant central spike within each spathe.

Because of the different origins of these calla species, it’s crucial to give them their preferred growing conditions. This means that the colored callas must be grown in light, fast-draining soil. They prefer full sun, but a little shade can help the blooms last longer.

These plants also require a dry dormancy. After they finish flowering in late summer, usually August, the leaves will begin to yellow.

“When the leaves turn yellow, it’s time to stop watering the plants and let them dry out and go dormant,” Lukens explained. “If the plants are in containers, simply put them out of sight and leave them alone until January, when they begin to grow again.”

If grown in the ground, special care must be taken with the plants.

Because too much water makes them susceptible to root or soil fungi, they need to be protected from winter rains. In early fall, lift the entire clump, including the soil, from the ground; dry the clumps, separate the rhizomes and store in a dry place such as a garage or basement. Plant them in early spring, back in the garden or in containers.

Another reason callas are prone to fail in the ground is that they have fragile roots. At this time of year, callas are available only as growing and flowering plants. The roots are very brittle and can be snapped easily if the plant is removed from the pot for planting in the ground. This makes the plant very susceptible to disease.

Lukens advises keeping the plant in its container. If you want to add the splash of color to your garden, set the plant, container and all, into the soil. (Be sure to remove it in fall to give it the dry dormancy time it needs.) In spring, rhizomes are available for planting in containers or in gardens with amended soils. They can also be grown successfully in fast-draining raised beds.

Colored callas do multiply, but not as fast as the white ones. They can probably stay in the same container for at least one year. When in doubt, pot up to the next larger container in early spring.

Lukens advises growing the colored callas in containers because it’s easier to monitor their water and fertilizer.

“These plants like to be grown on the dry side,” he cautioned. “Water only when at least the top one-third to one-half of the pot is dry. Feed with a balanced fertilizer every two weeks. Stop fertilizing in August, and begin again only when they’re actively growing next spring.”

Lukens advises freshening the container in late January by adding one inch of fresh potting soil and a teaspoon of time-release fertilizer.

Savvy gardeners simply place the containers out of sight, on their sides so rain or water won’t penetrate to the dormant calla rhizomes, and forget about them until early spring when they’re again given a place of honor in the garden or patio.

Colored callas are in full bloom now and are available at nurseries throughout Orange County.