Question:
When can I start calla lilies indoors?Answer:
Plant calla lily rhizomes 1 to 2 inches deep in a well-drained potting mix about 6 to 8 weeks before the average last spring frost in your area. After potting, water well and place the containers in a warm, 70 to 75°F location. Keep the potting mix moist, but not wet.
When foliage appears, move the plants to a sunny window or place them under fluorescent lights. Calla lilies should be planted outdoors after the danger of frost is past. Appropriate planting times would be early May in southern Iowa, mid-May in central portions of the state, and late May in northern counties. Before planting outdoors, harden or acclimate the calla lilies to outdoor growing conditions. Initially, place the plants in a shady, protected location and then gradually expose them to longer periods of sunlight. After they’ve been hardened, plant the calla lilies in a moist, well-drained soil in partial shade.
Learn more in this article: Planting and Caring for Tender Perennials.