The life cycle of a true lily (Lilium species) does not end when its vibrant flowers fade. The post-bloom period shifts the plant’s focus from reproduction to survival and preparation for the following season. Proper care during this time maximizes the bulb’s energy reserves. Managing the plant through the decline of its summer display ensures a robust and colorful perennial return.
Immediate Post-Bloom Pruning (Deadheading)
The first action after lily blossoms wither is the careful removal of spent flower heads, known as deadheading. This prevents the plant from diverting energy toward creating seeds. If the plant sets seed, it consumes resources that should be stored in the underground bulb.
To deadhead correctly, use clean, sharp shears to snip the faded flower or cluster just beneath the bloom, but above the leaves. This leaves the maximum amount of stem and foliage intact for the next phase. Do not cut down the entire main flower stalk, as it continues to support the remaining green leaves.
Nurturing the Foliage for Bulb Recharge
The requirement to leave the green foliage untouched is essential for post-flowering care. The leaves actively engage in photosynthesis, converting sunlight into carbohydrates for storage in the bulb. This energy storage determines next year’s bloom size and vigor.
Cutting the leaves too early is detrimental because it prematurely halts the energy-generating process. This results in a weakened bulb that may not flower the following year. The foliage must remain green until it naturally yellows and browns, indicating the bulb has absorbed all available nutrients. This decline typically occurs in late summer or early autumn.
During this period of active recharge, apply a suitable fertilizer. A granular or liquid feed low in nitrogen and high in potassium (potash) is ideal, such as a 5-10-10 ratio. Potassium assists in carbohydrate storage within the bulb, promoting a healthier root structure for dormancy.
Winterizing and Dormancy Preparation
Once the foliage has withered and browned, the plant enters dormancy, and the final cut can be made. For hardy, in-ground lilies, trim the dead stem down to about two to three inches above the soil line. Leaving a small stub serves as a marker and helps prevent damage to the bulb during winter maintenance.
In colder regions, applying a thick layer of protective mulch is beneficial. A four-to-six-inch layer of straw, shredded leaves, or wood chips provides insulation to stabilize the soil temperature and prevent the bulb from being damaged by freeze-thaw cycles. Apply this mulching after the ground has cooled but before it completely freezes.
Lifting and Storing Tender Bulbs
Tender lily varieties, such as Oriental hybrids in cold zones, or all lilies grown in containers, may need to be lifted and stored indoors. After the foliage dies back, gently dig up the bulbs, clean off excess soil, and allow them to dry for a few days in a cool, dark place.
The bulbs should then be stored in a ventilated container, nestled in a material like dry peat moss or vermiculite. Keep them at a temperature between 35 and 55 degrees Fahrenheit until replanting in spring.