Calla lilies (Zantedeschia) are popular ornamental plants prized for their elegant, chalice-shaped flowers and attractive foliage. These tender perennials grow from fleshy underground structures called rhizomes, which are often mistakenly referred to as bulbs. Calla lilies can be replanted and relocated successfully, a process often necessary for maintaining their health and vigor. Replanting allows for propagation, moving the plant to a more suitable location, or saving it from freezing temperatures during winter.
When and Why to Replant Calla Lilies
The optimal time to replant calla lilies is during their natural period of dormancy, after the growing season has ended. This window is typically in the late fall once the foliage has died back, or in the very early spring before new shoots emerge. Moving the plant while dormant minimizes stress on the root system and maximizes energy for re-establishing itself. In regions outside of USDA hardiness zones 8 through 10, fall replanting is mandatory to dig up rhizomes for overwintering indoors.
A primary reason for replanting is to combat overcrowding, which occurs as rhizomes multiply beneath the soil. Dense clumps cause plants to compete for nutrients and water, often resulting in a decline in flower size and quality. Gardeners should lift and divide clumps every three to five years to ensure continued robust flowering. Relocation is also common when a plant has outgrown its space or receives insufficient sunlight.
Digging, Preparing, and Dividing the Rhizomes
Excavating and Curing
The process begins with carefully excavating the rhizome mass, taking care not to damage the root systems. Start by digging a wide perimeter around the plant, typically about 6 to 12 inches away from the main stems. Gently lift the entire clump from the soil. Once the rhizome is out of the ground, gently brush away the excess soil, avoiding water which can encourage fungal rot.
It is advisable to let the excavated rhizomes dry out for at least one to two days in a cool, well-ventilated location. This allows the exterior to “cure” or form a protective layer.
Inspecting and Dividing
After the drying period, inspect the rhizome mass for any soft spots or signs of disease. Trim away any compromised tissue with a clean, sharp, and sterilized knife. The rhizomes can then be divided, either by hand where natural connections are loose or with a knife for more stubborn sections.
Each separated piece must contain at least one visible “eye,” which is a small bump or growth point. New foliage and roots will sprout from this eye. A division without an eye will not produce a viable plant, so ensure each new section is robust enough to support independent growth.
Replanting Steps and Initial Care
Site Preparation
The preparation of the new planting site is important for success. Calla lilies perform best in full sun to partial shade, with afternoon shade beneficial in intense heat. The soil should be rich in organic matter, consistently moist, and well-draining to prevent rotting. Amending the soil with compost before planting helps achieve this balance of moisture retention and drainage.
Planting and Watering
Position the rhizome with the growing points, or eyes, facing upward in the prepared hole. Cover the rhizome with 1 to 2 inches of soil. Space multiple divisions 12 to 18 inches apart to allow room for future growth. After settling the rhizomes, water thoroughly to eliminate air pockets. Water sparingly until you observe the first signs of leaf growth, then transition to a regular schedule that keeps the soil consistently moist.