The Calla Lily (Zantedeschia) is an ornamental plant prized for its elegant, sculptural bloom, which is technically a modified leaf called a spathe. Originating in Southern Africa, this plant is a fixture in modern garden designs and formal bouquets. The sleek, trumpet-shaped flowers rise above broad, dark green foliage. Despite its popularity, many wonder if its stunning display lasts throughout the entire warm season.
Understanding the Calla Lily Bloom Cycle
Calla Lilies are not continuous bloomers and do not typically flower all summer long. The duration of their display depends heavily on the specific variety. Most Zantedeschia species enter a natural rest period following their main flowering phase. The peak blooming season generally occurs in late spring and early summer, lasting six to twelve weeks.
The common white Calla (Zantedeschia aethiopica) is a rhizomatous perennial that behaves differently from its colorful counterparts. In frost-free climates, this species is semi-evergreen and lacks an obligate dormancy period. It can sustain a longer, more sporadic bloom from spring into autumn if conditions remain moist and mild. Conversely, the vibrant hybrid varieties (yellow, pink, purple, and red) are grown from tubers and have a shorter, more defined seasonal bloom. These hybrids require a mandatory resting phase after their flowering window closes, typically in mid-to-late summer.
Essential Care for Extended Flowering
To maximize the length and vigor of the flowering period, attention to environmental factors is necessary. Calla Lilies thrive with ample light, requiring at least six hours of bright, indirect sunlight daily for robust flower production. In regions with intense midday heat, providing partial afternoon shade prevents the blooms and leaves from scorching.
Consistent moisture is necessary throughout the active growing and flowering season, as these plants naturally grow in marshy areas in their native habitat. The soil should be kept uniformly moist but never waterlogged, which could lead to tuber rot. Applying a balanced, low-nitrogen liquid fertilizer every two to four weeks encourages the development of new flower stalks instead of just foliage growth.
A simple maintenance practice is deadheading, which involves removing the spent flower spathes before they form seed. This redirects the plant’s energy away from seed production and back into creating new flowers. Trimming the stalk cleanly near the base of the plant promotes subsequent blooms and maintains a tidy appearance.
Preparing Calla Lilies for Dormancy
When the plant’s natural cycle concludes, usually by mid-to-late summer, the foliage will begin to yellow and eventually die back. This is the plant’s signal that it is entering its necessary dormant period to store energy for the next season. Once this natural yellowing process begins, gradually reduce the amount of water provided to the plant.
For colorful hybrid varieties, which are tender and cannot survive freezing temperatures (colder than USDA Zone 8), the tubers must be lifted and stored in cold climates. After the foliage has withered, dig up the tubers, clean off excess soil, and allow them to cure for several days in a warm, dry location. Curing toughens the outer skin, reducing the risk of rot during storage.
The dried tubers should be stored in a cool, dark, and dry environment, such as a basement or garage, where the temperature remains consistently around 50°F. Placing them in a paper bag or covering them with dry peat moss or sawdust helps maintain the correct balance until they are replanted the following spring. The hardy white Zantedeschia aethiopica can often be left in the ground in milder zones with a protective layer of mulch.