Calla Lilies (Zantedeschia) bring an elegant, architectural beauty to any garden space, prized for their striking, funnel-shaped flowers and lush foliage. Although often referred to as “bulbs,” these plants actually grow from a modified underground stem structure known as a rhizome. The planting process for these rhizomes is straightforward, but understanding their specific needs ensures a successful display of color. This guide provides clear, practical instructions for planting Calla Lily rhizomes.
Site Selection and Timing
Plant Calla Lily rhizomes in the spring, after the last expected frost has passed. Calla lilies are sensitive to cold, so the soil temperature is a more accurate indicator than the calendar date. Planting should be delayed until the soil has warmed and stabilized to at least 60°F to 65°F.
Selecting the right location is important for the plant’s health and bloom production. Calla lilies thrive best in a site that receives full sun (six or more hours of direct sunlight daily), especially in cooler northern climates. In regions with intense summer heat, a location that provides partial shade during the harsh afternoon hours will prevent scorching.
The soil must be rich in organic matter and, most importantly, possess excellent drainage. Calla lilies prefer consistent moisture but will suffer from rot if the rhizomes sit in soggy conditions. If your native soil is heavy clay, it should be amended with materials like compost, well-rotted manure, or peat moss to improve porosity and aeration. This preparation encourages robust root development.
Step-by-Step Planting Guide
Once the site is prepared, use a trowel to dig a planting hole that is approximately 2 to 4 inches deep, depending on the size of the rhizome. The goal is to cover the rhizome completely without burying it too deeply, as this can inhibit sprouting.
Proper orientation of the rhizome is a defining factor in planting success. Calla rhizomes possess small, knobby points known as “eyes” or growth tips, where the new shoots will emerge. Place the rhizome into the prepared hole with these eyes facing upward toward the soil surface.
For garden beds, Calla Lilies should be spaced 12 to 18 inches apart to allow for adequate air circulation and foliage growth. Once the rhizome is positioned, gently backfill the hole, covering it with the amended soil. Lightly firm the soil over the rhizome to eliminate air pockets that could dry out the developing roots.
Planting Calla Lilies in small clusters of three or more rhizomes creates a visually impactful display. Maintaining the recommended spacing, even when planting in groups, prevents overcrowding and reduces the risk of fungal diseases.
Initial Watering and Care
Immediately following the planting process, the rhizomes require a thorough watering to settle the surrounding soil. This initial soaking helps the soil make firm contact with the rhizome, which is necessary for root establishment. Apply the water slowly and deeply until the entire planting area is evenly moistened.
The moisture requirements change subtly during the initial establishment phase. Water sparingly after the first soaking, maintaining a lightly moist environment without making the soil soggy. Overwatering before the shoots appear can easily lead to rhizome rot, as the plant is not yet actively drawing up water.
You should begin to see the first signs of growth, typically small sprouts, emerging from the soil within two to four weeks of planting. Once the leaves have fully emerged, the watering frequency can be increased to keep the soil consistently moist, but never waterlogged. Monitor the new foliage for common garden pests, such as slugs and snails, which can damage the tender young shoots.