The Calla Lily (Zantedeschia) is an ornamental plant admired for its elegant, trumpet-shaped blooms. While it is most commonly propagated through the division of its rhizomes, growing new plants from seed is a viable, though less frequent, method. This approach allows gardeners to potentially develop new color variations.
Anatomy of the Calla Lily Fruit
The seeds of the Calla Lily develop within a structure that forms after the spathe and the central spadix begin to wither. Following successful pollination, the spadix, which houses the true flowers, swells and develops into a thick, fleshy, berry-like fruit. This resulting structure often resembles a small, dense cone and is initially a bright green color.
This developing fruit must remain on the plant for several months after flowering to allow the seeds inside to reach maturity. A change in the fruit’s color indicates viability, as the exterior transitions from firm green to a softer yellow, orange, or light brown hue. When fully ripe, the entire cone-like structure will feel slightly mushy to the touch, signaling that the seeds are ready for harvest.
Distinctive Features of the Seeds
The seeds are found encased within the individual, kernel-like segments that make up the cone-shaped fruit. These segments are small, fleshy compartments, each containing one to five true seeds. A mature Calla Lily seed is quite small, typically measuring around two millimeters in diameter.
When freshly extracted from the pulp, the seeds are generally roundish or slightly oval in shape, often possessing a somewhat irregular contour. Their color is a pale yellowish-orange or a lighter tan, and they frequently have a distinctly sticky texture due to the surrounding fruit pulp.
Upon drying, the seeds will take on a darker, more muted brown or deep tan coloration. The surface texture of the mature seed is often slightly wrinkled or rough, giving it a somewhat miniature tuber-like appearance. A successful harvest relies on recognizing these small, firm objects after separating them from the soft, outer fruit material.
Handling and Preparing Seeds for Planting
Cleaning and Drying
Once the fully ripened fruit has been collected, the seeds must be carefully extracted and cleaned before storage or sowing. The first step involves removing the seeds from their sticky, fleshy fruit pulp, which is done by gently crushing the kernels and rinsing the contents under water using a fine-mesh sieve. Removing this pulp is important because the residual sugars can encourage mold growth and inhibit germination.
After cleaning, the seeds should be spread out to dry thoroughly for about one to two weeks. This drying phase is necessary for preservation if the seeds are to be stored for later planting.
Stratification and Sowing
Calla Lily seeds often exhibit better germination rates when sown while fresh, or shortly after drying. For optimal germination, the seeds benefit from a period of moist stratification, which mimics natural winter conditions.
This can be achieved by placing the dried seeds in a damp paper towel inside a sealed plastic bag and refrigerating them for several weeks. Following this pre-treatment, the seeds are ready to be planted shallowly, approximately a quarter-inch deep, in a warm environment to encourage sprouting.