The Tiger Lily (Lilium lancifolium) is a stunning perennial celebrated for its vibrant orange, black-spotted blooms. Gardeners often wonder about its ability to spread, and the answer is yes: it is an exceptionally vigorous and quick multiplier. This rapid proliferation, which can be aggressive, is driven by unique reproductive structures. These mechanisms allow the plant to colonize an area readily without relying heavily on traditional seed production, explaining why a single plant quickly establishes a dense, flowering clump.
The Primary Mechanisms for Spread
The Tiger Lily employs two distinct asexual methods to ensure its rapid and widespread multiplication. The first involves structures called aerial bulbils. These small, dark, pea-sized buds form in the leaf axils, which is the point where the leaf joins the main stem of the plant.
As the season progresses, these bulbils mature, eventually dropping to the ground near the parent plant. Upon contact with the soil, the bulbils root themselves and begin to grow as genetically identical clones of the original lily. This mechanism allows the plant to “walk” across the garden.
A second, more common method of spread among all lilies is the production of underground offsets, or bulblets. The main bulb naturally generates smaller, daughter bulbs clustered around its base. As the mother bulb ages, these offsets separate and grow into new individual plants, which is a process known as division. If left undisturbed, these offsets contribute to a rapidly expanding, overcrowded clump of lilies beneath the soil surface.
Managing Prolific Growth
The Tiger Lily’s efficiency in multiplication means that gardeners must often intervene to prevent overcrowding and unwanted spread. One of the most effective management strategies involves the removal of the aerial bulbils. Picking off these small, black structures from the leaf axils before they fall to the ground in late summer will significantly limit the number of new plants that sprout the following season.
Regular maintenance also includes the practice of deadheading, which is the removal of spent flowers. While the primary spread is vegetative, removing the dead blooms prevents the plant from expending energy on developing seeds. This directs that energy back into the main bulb and root system.
A clump of Tiger Lilies will become congested after a few years, which can lead to smaller blooms and reduced vigor. To address this subterranean overcrowding, the main bulb clump should be lifted and divided every three to four years. This process is typically done in the fall after the foliage dies back or in early spring before new growth appears. It involves carefully separating the offsets and replanting them immediately at a healthy distance. This thinning process refreshes the patch, ensuring each plant has adequate space and nutrients to produce the largest possible flowers.
Intentional Propagation Techniques
The plant’s natural reproductive mechanisms can be intentionally harnessed by gardeners to create new lilies for desired locations. The aerial bulbils, once they are dark and firm, can be easily collected in late summer. These harvested bulbils can then be planted in prepared soil approximately one-half inch deep, similar to planting small seeds.
Patience is required as these tiny new bulbs take time to mature. A bulbil planted in the fall will typically produce a small leaf the next spring, but it may take two to three years of growth before the new plant is large enough to produce its first flower.
A faster method for generating new, large plants involves utilizing the underground offsets. These offsets are best separated and transplanted when the main clump is lifted for division in the fall. Each offset, which is essentially a fully formed small bulb, can be replanted at the same depth as a mature bulb in its new location. By using these vegetative parts, gardeners can strategically place genetically identical clones of the parent plant across their landscape.