Calla lilies (Zantedeschia) are popular ornamental plants prized for their elegant, trumpet-shaped blooms and striking foliage. These beautiful flowers, which grow from rhizomes (often called bulbs), are well-suited for container gardening, allowing growers to enjoy their tropical appeal. A common challenge is determining the optimal number of rhizomes that can comfortably fit into a single pot. This requires calculating the necessary spacing and selecting an appropriately sized container to support the plants’ development.
Determining Bulb Density Based on Size
The number of calla lily rhizomes you can plant in a pot is determined by the required space each plant needs to thrive. A common guideline for container planting is to space the rhizomes closer than you would in the garden, typically around 4 to 6 inches apart on center. For a denser, more immediate visual impact, you can plant the rhizomes as close as 1 to 2 inches apart, provided they are not touching. This closer spacing works in pots because the confined space naturally limits the overall growth of the clump while still allowing enough root development for flowering.
Planting depth is consistent, generally ranging between 1 to 3 inches below the soil surface. Rhizomes should be positioned with the “eyes,” or growing tips, facing upward. For example, a 10-inch diameter pot accommodates two to three rhizomes using the wider spacing guideline. A 12-inch pot allows for three to five rhizomes, depending on the exact spacing chosen.
Selecting the Appropriate Container
The container’s dimensions dictate the maximum number of rhizomes you can plant. For standard calla lily varieties, a pot should have a minimum diameter of 10 to 12 inches to provide adequate surface area for spacing. The depth of the container is equally important, as it must accommodate the root system and a proper drainage layer. Select a pot that is at least 8 to 10 inches deep for the rhizomes to establish fully.
The pot’s diameter determines the available circular space, which translates into how many rhizomes can be spaced correctly. Containers must have adequate drainage holes, as these plants require consistently moist but not waterlogged soil to prevent the rhizomes from rotting. The pot material also affects soil moisture; porous terracotta pots allow for faster evaporation, while plastic pots retain moisture more efficiently.
Immediate Planting and Watering Steps
Once the appropriate container size and rhizome density are determined, planting begins with a well-draining potting mix. The rhizome should be placed with the growing tips pointing toward the sky, typically about 2 to 3 inches deep in the soil. After positioning the rhizomes, gently firm the soil around them to eliminate any large air pockets.
The initial watering step settles the soil around the rhizomes and activates the growth process. Water the pot thoroughly until excess water drains freely from the bottom holes. Following this initial soak, water sparingly until the first few leaves begin to emerge above the soil line. The newly planted pot should be placed in a location that receives the recommended light conditions, which is typically full sun to partial shade, depending on the climate.