Calla lilies grow in both large and small varieties with wide, bright-green leaves and colorful, tube-shaped flowers in pink, orange, red, purple, yellow and white. As perennial bulb plants, callas live for many years blooming repeatedly from the same bulbs. Continuous blooming within a given summer depends on variety, planting and care.
Calla lilies grow in many varieties with different sizes, colors of blooms, growth habits and blooming times depending on cultivar. A way to encourage blooms from spring to fall is planting early, midseason and late-blooming cultivars around the garden.
Calla lilies bloom at their given time and maintain blooms for many weeks before fading. Callas that feature early or mid-season blooming schedules may produce several flushes of blooms during the season, for summer-long flowes.
Calla lily bulbs require the right planting and care if they’re to grow and bloom at all. Plant calla bulbs in spring after the last frost, in sites that get full sunshine and moderately good drainage. Give them 12 to 18 inches of space each, with more space for the larger cultivars. Amend soil to 6 inches with 3 inches of organic compost to loosen it for planting, then add bone meal for efficient root growth. Plant calla bulbs at a depth of 3 to 4 inches and water the plants with 2 inches of water a week through the growing season.
Callas stop producing flowers in the fall when cool temperatures and frost kill back their blooms and foliage. Allow the foliage to yellow and die on its own at this time, as they provide nutrition for the bulbs’ use in future growth. Gardeners in U.S. Department of Agriculture Plant Hardiness Zones 8 and up can leave calla bulbs in the ground for winter to achieve regrowth in spring, while gardeners in zones 7 and below must dig up the bulbs, store them inside for winter protection and replant them in spring.