The Calla Lily (Zantedeschia) is a popular flowering plant, though its underground structure is technically a rhizome or tuber, not a bulb. This structure stores energy for the plant’s growth. Proper orientation of the rhizome when planting is directly linked to successful sprouting. Placing the growth points correctly ensures the shoots expend minimal energy reaching the soil surface, while incorrect placement can delay or prevent the emergence of foliage and blooms.
Identifying the Growth Points
Determining which side of the Calla Lily rhizome faces upward requires visual inspection of the structure. The top surface, where new growth will originate, is generally flatter or slightly concave. This upper side contains small, bumpy protrusions known as “eyes” or growth nodes. These nodes are the dormant points from which shoots will emerge and may appear as pinkish or whitish bumps.
Conversely, the bottom side of the rhizome is typically smoother and more rounded or convex. This surface may also show evidence of the previous season’s root system, appearing as dried remnants. When planting, position the rhizome so the side bearing the growing tips points upward. If the top side is not immediately obvious, planting it sideways is an acceptable alternative. The plant will naturally correct its growth path toward the light, though initial shoot emergence may be slightly slower.
Preparing the Planting Site
Successful Calla Lily cultivation begins with preparing an appropriate growing medium. These plants thrive best in rich, well-draining soil that prevents water accumulation and avoids rot. Incorporating organic matter, such as compost or peat moss, improves nutrient content and soil aeration. The ideal time for planting Calla Lily rhizomes outdoors is in the spring, after the final threat of frost has passed and the soil has warmed.
Once the soil is prepared, the correctly oriented rhizome should be placed two to four inches beneath the surface. This depth provides insulation and physical anchorage for the developing plant. Planting too shallowly exposes the rhizome to temperature fluctuations, while planting too deeply can cause the shoot to exhaust its stored energy. When planting multiple rhizomes, maintain appropriate spacing for mature growth and air circulation. Leave 12 to 18 inches between each planting location.
Immediate Post-Planting Care
After covering the rhizome, the first step is a deep, thorough watering to settle the soil and eliminate air pockets. This initial saturation is important for triggering the rhizome to emerge from dormancy. Consistent moisture levels must be maintained throughout the establishment period, but the soil must never become soggy. The soil should feel evenly moist, as excessive water can lead to rhizome rot.
The Calla Lily requires specific light conditions to support sprouting and flowering. Placement in an area that receives full sun to partial shade is recommended for optimal growth. Full sun locations are generally better in cooler summer areas, but partial shade is preferred in regions with intense afternoon heat. Providing afternoon shade in hotter climates prevents the leaves from becoming scorched. Shoots typically appear within two weeks, and flowers can be expected within 13 to 16 weeks.