The Gladiolus, often called the sword lily, is a popular summer-flowering plant grown from a corm. These showy flowers bloom sequentially along a central stalk, offering vibrant color to the garden. Deadheading, the practice of removing spent flowers, is routine maintenance that significantly influences the plant’s health and future performance. Proper technique ensures the plant’s resources are directed toward the structures that guarantee next year’s impressive display.
Why Deadheading Gladiolus is Important
Removing fading flowers prevents the Gladiolus from expending energy on seed set. The plant’s biological imperative after blooming is to produce seeds for reproduction, which requires substantial resources. Interrupting this cycle redirects the plant’s energy away from seed formation and back into the underground corm. This energy storage allows the corm to strengthen and mature, resulting in a healthier, more robust plant capable of producing larger blooms the following season. Furthermore, removing wilted florets instantly improves the aesthetic appearance of the flower spike, and decaying flowers can also harbor fungal pathogens, so their removal reduces the risk of disease spreading.
Step-by-Step Instructions for Removing Spent Blooms
The deadheading process involves two distinct stages: removing individual spent florets and then cutting the entire spike. Start by inspecting the flower spike as the lower blooms begin to wilt and shrivel. Pinch or snip off these individual spent flowers, ensuring you remove the entire flowering structure, including the swollen base where the seed would form. This ongoing removal every few days keeps the spike looking fresh while the upper blooms continue to open.
Once all flowers on the main stalk have finished blooming, remove the stalk itself. Use clean, sharp bypass pruners or shears for a clean cut that minimizes damage and disease transmission risk. The location of this final cut ensures the corm receives maximum energy. Make the cut on the flower stalk just above the highest remaining leaf on the stem.
Leaving as much foliage attached as possible is necessary for the corm’s development. The leaves must remain to continue photosynthesis, which generates the carbohydrates the corm needs to store. Aim to leave at least four full leaves on the plant after the flower spike is removed. Cutting the stalk too far down prematurely limits the plant’s ability to gather energy reserves.
Care After the Flower Spike is Gone
After the flower spike is removed, the focus shifts entirely to nourishing the foliage and the corm below ground. The remaining leaves are the plant’s engine, responsible for gathering and transferring energy to the underground storage organ. Resist the urge to cut this green foliage back, even if the garden bed looks less tidy.
Continue to water the plant regularly, ensuring the soil remains evenly moist as the corm matures. This post-bloom period, lasting approximately six to eight weeks, is when the corm builds up the reserves needed to produce next season’s flower. Continue a light, balanced fertilization routine until the foliage naturally begins to turn yellow.
In colder climates (USDA Hardiness Zones 2 through 7), the corms are not reliably winter hardy and must be lifted for storage. Wait until the foliage has completely yellowed and died back, often after the first light frost, before gently digging up the corms. After lifting, the corms must be cured in a warm, dry, and airy location for two to three weeks until the outer husks are papery. They are then stored in a cool, dark, and well-ventilated space (35 to 50 degrees Fahrenheit) until replanting the following spring.