True lilies, belonging to the genus Lilium, produce seeds as part of their natural life cycle. They utilize sexual reproduction to create genetic diversity and viable seeds. While they rely on this method to generate new varieties in the wild, lilies are most commonly propagated by gardeners and commercial growers using quicker techniques. The ability of a lily to reproduce both sexually and asexually provides a versatile strategy for survival.
The Process of Seed Formation
The lily flower, once pollinated, develops a dry seed capsule. After the petals fade, the ovary at the base of the flower swells to form a three-chambered structure. This capsule remains on the stem throughout the summer, requiring six to eight weeks to fully mature and dry out. The fruit changes color from green to a brittle, light brown when fully ripe, usually in late summer or early autumn.
Inside this dried capsule, the mature seeds are stacked in vertical columns within the three compartments. Each seed is thin, flat, and brown, surrounded by a papery wing-like coating. This structure aids in wind dispersal, allowing the lightweight seeds to be carried away from the parent plant.
Asexual Reproduction Via Bulbs
Despite their capacity to produce seeds, lilies are often propagated through asexual methods because these techniques yield results much faster. Asexual reproduction bypasses the long maturation time and produces genetically identical clones of the parent plant. This cloning process is highly favored in commercial horticulture to keep hybrid varieties true to type.
The most common natural method is the division of the underground bulb, which splits to form offsets or bulblets. Some species, like the Tiger Lily, also generate tiny, black bulbils in the leaf axils along the stem. Scaling involves removing the fleshy scales of the main bulb and incubating them, causing small bulblets to form. These methods reduce the time to flowering from several years to just one or two seasons.
Growing Lilies from Seed
Propagating lilies from seed is primarily employed by breeders looking to create new hybrids or by enthusiasts aiming to grow unusual species. The time commitment is considerable, as it generally takes between two and three years for a seedling to produce its first flower, with some species requiring up to seven years. Seeds should be collected when the capsule turns brown and begins to split, indicating they are ready for harvest. The seeds must then be separated from the pod and stored in a cool, dry place until they are ready for sowing.
Lily seeds exhibit different germination patterns, which dictates the required preparation and sowing method. Quick-germinating types, classified as epigeal, send a cotyledon (seed leaf) above ground soon after planting and do not require a cold period. Delayed-germinating types, categorized as hypogeal, first form a tiny bulb underground and require a period of warm stratification followed by a period of cold stratification before a true leaf will emerge. This complex two-stage process mimics the natural cycle of a seed falling to warm soil in the summer, forming a bulb, and then undergoing a cold winter dormancy before sprouting the following spring. Sowing hypogeal seeds often involves using moist medium in sealed bags, subjecting them to specific temperature cycles to break dormancy and encourage germination.