How to Grow Calla Lilly Bulbs

Remove the weeds and grass from the planting site after all danger of spring frost is past. Choose an area with afternoon shade and moist soil. Mix 3 inches to 4 inches of compost into the top 8 inches of soil with a shovel. Plant the calla lily bulbs so the tops of the bulbs are 2 inches from the surface and 12 inches to 24 inches apart.

Sprinkle the planting area with water until the moisture reaches the depth of the bulbs. Calla lilies like wet soil, so water whenever the soil starts to dry out. The goal is to keep the top 2 inches to 4 inches wet.

Spread a 1-inch layer of mulch such as wood chips over the planting area. Mulch prevents quick evaporation of moisture from the soil. As the calla lilies grow, refresh the layer of mulch to keep it at the 1-inch depth.

Broadcast 20-20-20 slow-release fertilizer over the area after planting. Water the area right away to activate the fertilizer. Use half-strength water-soluble balanced fertilizer every two weeks while the calla lily is actively growing. Stop feeding the calla lilies when the flowers start to die.

Remove the fading flowers by cutting the stems with a sharp knife. This keeps the flowerbed tidy and neat. Wet weather can cause leaf spot fungus to damage the leaves. Remove the injured leaves in order to control the fungus.