The true lily (Lilium) is a popular perennial bulb known for its magnificent, often fragrant, trumpet-shaped or recurved flowers. These robust plants offer a spectacular mid-summer display and return reliably year after year with consistent care. This guide provides practical steps for maintaining a healthy Lilium plant throughout the seasons, ensuring the bulb stores energy for continuous, vibrant blooms.
Essential Environmental Setup
Proper planting location and soil preparation are fundamental to the lily bulb’s long-term success. Lilies thrive best when the plant receives full sun, defined as six or more hours of direct sunlight daily, which is necessary for robust flowering. However, they prefer to have their roots kept cool, a condition often referred to as “head in the sun, feet in the shade.” This is achieved by planting low-growing groundcovers around the base of the lily stems to shade the soil surface.
Excellent drainage is crucial, as the fleshy bulbs are highly susceptible to rot in saturated conditions. Heavy clay soils should be amended extensively with organic matter or coarse grit to improve permeability. The ideal soil is loose, rich in organic material, maintaining a neutral to slightly acidic pH (6.0 to 7.0).
Planting depth is significant because many lilies are stem-rooting, producing roots along the stem above the bulb. Generally, the bulb should be planted at a depth of approximately 6 to 8 inches, or two to three times the height of the bulb itself. This deep planting helps anchor the tall stem and promotes the development of stabilizing stem roots. Bulbs should be spaced 8 to 18 inches apart to allow for good air circulation and future growth as they multiply.
Seasonal Watering and Feeding
During the active growth period of spring and summer, lilies require consistent moisture to support their rapid development and large flowers. They should be watered deeply but infrequently, aiming to keep the soil moist but never waterlogged. Water is particularly important during dry spells, especially when the plant is setting buds and flowering.
It is best to water the plant at the base, directing the stream of water toward the soil rather than over the foliage. Overhead watering can create moist conditions on the leaves, which increases the risk of fungal diseases. A layer of organic mulch, applied once the shoots emerge, helps conserve soil moisture and keeps the root zone cool.
Lilies benefit from regular feeding throughout the growing season. In early spring, apply a balanced, slow-release fertilizer, such as a 10-10-10 formulation, when the shoots first emerge to support vigorous stem and leaf growth. As the plant prepares for and enters the blooming phase, switch to a low-nitrogen, high-potassium fertilizer (e.g., 5-10-10). This change in nutrient balance encourages flower production and aids the bulb in storing energy for the following year.
For taller varieties that exceed three feet, a support stake should be placed near the bulb at planting time. This prevents the heavy flower heads from causing the stem to bend or snap in wind.
Post-Bloom Management and Dormancy
Once the lily flowers have faded, the goal of post-bloom management is to redirect the plant’s energy away from seed production and back into the bulb. The spent flowers should be removed promptly, a process known as deadheading, which prevents the formation of seed pods. This action signals to the plant that it should focus its resources on replenishing the bulb.
The most important step after flowering is resisting the urge to cut back the foliage, even when it appears less attractive. The green leaves and stem are responsible for photosynthesis, the process that creates and stores energy in the bulb for the next blooming cycle. The stalk and leaves must be left completely intact until they naturally yellow and die back, typically in the late fall.
Only after the foliage has fully withered and turned brown should the stem be cut down to just above the soil line. For the winter, bulbs in cold climates benefit from a 4 to 6-inch layer of protective mulch, which helps insulate the soil and prevents frost heaving. In areas with extremely wet winters, ensuring the soil remains well-drained is paramount to prevent the dormant bulb from rotting.