Calla lilies (*Zantedeschia spp.*) are perennial plants that naturally propagate through rhizomes, which are underground stems capable of producing new shoots and roots. Division is a reliable method to propagate these plants, as it mimics their natural growth habit. By dividing the rhizomes, you encourage the plant to produce multiple offspring, ensuring genetic consistency and healthier growth compared to seed propagation.
The best time to divide calla lilies is during their dormant period, typically in late fall or early spring. During dormancy, the plant's energy is concentrated in the rhizomes, making it less stressful for the plant to undergo division. Avoid dividing during active growth or flowering, as this can shock the plant and reduce its vigor.
Before dividing, water the calla lily thoroughly a day or two in advance to ensure the rhizomes are hydrated. Gently dig around the plant to lift the entire clump from the soil, taking care not to damage the rhizomes. Shake off excess soil to expose the rhizome structure, and rinse it lightly if necessary to identify natural divisions.
Healthy rhizomes are firm, plump, and free of rot or damage. Look for natural separations where the rhizome branches, as these are ideal points for division. Using a clean, sharp knife or pruning shears, cut the rhizome into sections, ensuring each division has at least one growth point (or "eye") and a portion of healthy roots. Discard any soft or discolored sections to prevent disease spread.
After division, allow the cut surfaces of the rhizomes to air-dry for a few hours to form a callus. This step reduces the risk of fungal or bacterial infections. Optionally, you can dust the cuts with a fungicide or rooting hormone to further protect and stimulate root development.
Choose a well-draining planting site or container with fertile, slightly acidic soil. Plant each rhizome division horizontally, about 3-4 inches deep, with the growth point facing upward. Space divisions 12-18 inches apart to allow for future growth. Water lightly after planting to settle the soil, but avoid overwatering, as calla lilies are susceptible to rot in soggy conditions.
Place newly planted divisions in a location with bright, indirect light and consistent moisture. Avoid direct sunlight until new growth appears. Fertilize lightly with a balanced fertilizer once shoots emerge to support healthy development. Monitor for pests or diseases, and remove any dead foliage to maintain plant hygiene.
Within a few weeks, the divisions will begin producing new shoots and roots. Continue regular watering and provide partial shade if temperatures rise excessively. As the plants establish, they will resume their natural growth cycle, eventually flowering in their next growing season.
