Calla lilies are the quintessential bouquet flower. The bulbs of this African flower are usually described as exotic, sensual, and suggestive and have graced the vases at countless weddings and are used in bouquets around the world. It's easy to see why these graceful and elegant flowers are easy to love.
What Kind of Flower Are They?
As with any plant in such high demand, there are many varieties of the basic plant. They have been bred for size and shape and even color. Calla lilies—not actual lilies at all—are aroids which means they come from the arum family of plants or Araceae. What distinguishes this family is that their flowers are borne on a type of inflorescence or a cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches.
It is a rhizomatous plant that means it has a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks. It is a perennial plant, which in the right growing conditions after it dies off after summer, can grow back year after year from its root system.
Calla lilies like dappled sunlight or even light shade, along with high temperatures, high humidity, lots of fertilizer, and ample water during the growing season followed by a cooler and drier dormant period during the late fall and early winter. If you have a glasshouse, or better yet, a hydroponics set-up, you can grow beautiful calla lilies. Even if you don't, though, you can keep the plants going for at least one growing season.
- Light: The plants prefer bright, indirect light during the growing season. The plants dislike direct sunlight.
- Water: Keep potted and blooming plants constantly moist. As the blooms fall, reduce watering until all the flowers are gone; then let the leaves wither and die as the plant dries out. Give it a brief resting period, then repot it in late winter into fresh soil and begin watering again to encourage new sprouts.
- Temperature: Keep the temperature on the warm side (up to 80 F) during growth and blooming. During the dormant period, cool it down to 50 F.
- Soil: The best substrate for it is a loose, well-drained potting mix.
- Fertilizer: Fertilize it during the growing season with liquid fertilizer or controlled-release fertilizer according to the label instructions. Stop fertilizer during dormancy.
Calla lilies can be propagated from the old rhizomes by division. Outside, over time, plants will form large clumps that can be easily divided into smaller units. However, calla lilies are only viable outside in USDA zones 10 or 11 (which is basically places that rarely have freezing temperatures like southern California, southern Florida, and Hawaii), so most Americans growing calla lilies will be growing pot-bound specimens.
Unfortunately, while rhizome division is still possible with indoor specimens, over time the plants will begin to lose vigor, and their flowers will never regain their original strength. So unless you are very attached to propagation, it's probably a good idea to discard expended plants and buy new ones.
Repotting should be done in the mid-winter after the plant has gone into its dormant phase and rested in a cool place in its spent soil. To repot, remove the rhizome from the old pot and place into the fresh soil (smooth side down) in a slightly larger pot. Begin watering immediately to encourage new growth.
The basic calla lily is a Zantedeschia hybrid. The most common variety features a yellow spadix (which is a long middle spike) surrounded by a white spathe, or a large sheath enclosing it. Recent breeding efforts, however, have introduced flowers with deep red spathes, or even mixed or speckled specimens. The typical calla lily will grow to a height of 36 inches outdoors, but shorter hybrids have been produced with Z. rehmanii that stay about 12 inches tall and are perfect for desktops.
Calla lilies are such beautiful plants; it's hard not to splurge on one occasionally.
- While they are growing and blooming, keep them adequately fertilized and watered, misting the plant every so often to keep the ambient humidity high.
- Plants that are exposed to direct sunlight will develop damaged flowers, so watch out for leaf tip burn or discolorations.
- They are susceptible to aphids (plant lice).
- If you want to keep your plant after the bloom is finished, snip off the flowers and the fading leaves, only slowly reducing water, until the plant totally fails.
- Although it can be fun to rejuvenate a plant from the rhizome, it will never achieve the same bloom, so it might be wiser to think of calla lilies like phalaenopsis orchids, which are somewhat disposable after the bloom is finished.