Lifting tulip bulbs, also known as digging or dividing, is a horticultural task undertaken for several reasons. Gardeners often lift bulbs to prevent overcrowding, which reduces the size and vigor of future blooms. Removing the bulbs allows for division of offsets and proper spacing when replanted in the fall. This process is also necessary in warmer climates where summer heat and soil moisture can cause bulbs to rot. By digging up and storing the bulbs, growers control the environment, mimicking the cool, dry dormancy tulips require to regenerate and thrive for the next season.
Visual Cues for Timing the Lift
The most important factor in determining when to dig up tulip bulbs is the condition of the foliage, which signals that the bulb is ready. After the tulip flower fades, the leaves must remain attached to the plant for about six weeks. During this time, the foliage acts as a solar collector, transferring vital starches and carbohydrates back into the underground bulb. This energy reserve is necessary for the bulb’s survival through dormancy and the formation of next year’s flower bud.
The correct time to lift the bulbs is when the leaves have fully matured, turned straw-yellow, and begun to wilt or flop over. The foliage must be clearly dying back, but should not yet be entirely brown. Cutting green leaves prematurely compromises the bulb’s ability to store energy, often resulting in a “blind” bulb that fails to flower. Waiting until this stage ensures the nutrient transfer process is complete, guaranteeing robust blooms.
Safely Removing and Preparing Bulbs
The physical process of digging requires a careful approach to avoid damaging the bulbs clustered beneath the soil. A garden fork is the preferred tool over a spade because it is less likely to slice or puncture the bulb while loosening the soil. Insert the fork approximately six inches away from the base of the yellowing stem. Gently rocking the fork back and forth will loosen the soil, allowing the entire cluster of bulbs to be lifted.
After lifting, prepare the bulbs for storage by removing debris and inspecting for health. Shake off excess soil, but avoid washing the bulbs with water, as moisture promotes rot. Use clean garden shears to trim away the dead foliage and old roots, leaving only a short stem stub attached. Inspect each bulb carefully, discarding any that feel soft, mushy, or show signs of mold or damage, as these can spread disease.
Curing Bulbs for Dormancy
The curing process is a necessary drying period that prepares the bulbs for long-term dormancy by hardening their outer layers. Place the cleaned bulbs in a single, non-touching layer on a wire rack or tray in a dry, dark, and well-ventilated location. Good air circulation is essential, helping the outer skin (tunic) dry out and form a protective papery barrier. This hardening prevents moisture loss and protects the bulb from fungal pathogens during summer storage.
Curing typically takes between a few days to two weeks, depending on ambient humidity and temperature. The goal is for the outer layer to feel completely dry and papery to the touch. A cool garage, shed, or basement out of direct sunlight is an ideal environment for this initial drying period. Once cured, the bulbs are ready for separation and storage until the autumn planting season.
Storing Bulbs Until Replanting
For successful long-term storage until replanting in the fall, the environment must mimic the cool, dry conditions of a natural dormant period. The ideal temperature range is typically between 50 and 65°F (10 and 18°C). Higher temperatures can cause the bulbs to dry out excessively. Maintaining low humidity is also important to prevent the onset of mold or rot.
Bulbs must be stored in containers that allow for continued air circulation to prevent moisture buildup. Sealed plastic bags or containers trap humidity and should be avoided. Superior choices include mesh bags, net bags, or ventilated crates. Label the containers and periodically inspect the stored bulbs throughout the summer months. Any bulbs that appear softening, molding, or sprouting should be immediately removed to protect the viability of the healthy stock.