The management of tulip bulbs following their spring display is crucial for their ability to flower in subsequent seasons. Once the petals have dropped, the plant begins a necessary period of energy accumulation. The fundamental goal of post-bloom care is to ensure the underground bulb stores sufficient carbohydrates for the next cycle of growth. Timely intervention and correct handling maximize the bulb’s viability.
Essential Care After Flowering
The first action after a tulip has finished blooming is deadheading, which means removing the spent flower head. This practice is necessary to prevent the plant from diverting energy into producing seeds, a process that significantly depletes the bulb’s reserves. The flower stem should be clipped just below the faded bloom, leaving the main stem and all the foliage intact.
Allowing the foliage to yellow and die back naturally is the most important step for perennializing tulips. The leaves continue to perform photosynthesis, manufacturing the sugars that are transported down to the bulb for storage. Cutting the green leaves prematurely interrupts this carbohydrate production, effectively starving the bulb. This natural dieback process usually takes between four and eight weeks after the bloom period ends.
Supplemental feeding can be beneficial during this recharge phase. Applying a low-nitrogen, slow-release fertilizer provides the nutrients needed to support the energy-storing process. Water should be moderated, allowing the soil to dry slightly between waterings to prevent the dormant bulb from rotting. The foliage is ready to be removed only when it has turned completely brown or straw-colored.
Deciding to Lift or Leave Bulbs
A key decision for the gardener is whether to leave the bulbs in the ground to naturalize or to lift and store them for the summer dormancy. This choice is largely dependent on the specific tulip variety and the local environmental conditions. Many modern hybrid tulips, especially the highly-bred, “fancy” types, are less vigorous and tend to decline in performance if left in the ground year after year.
The local climate plays a major role in this decision, particularly concerning soil moisture. Tulips originate from regions with dry summer climates, and excessive moisture during their dormant period can lead to rot and fungal diseases. Gardeners in areas experiencing high summer rainfall or very wet winters should consider lifting their bulbs to protect them from rotting.
Conversely, species tulips (botanical tulips) and certain robust varieties, such as Darwin Hybrids, are much better suited to being left in the soil. These types are more likely to perennialize successfully, especially in climates that provide a sufficiently cold winter chilling period and relatively dry summer soil. If the bulbs are left in place, they should be divided every few years if flowering becomes sparse, which indicates overcrowding.
Preparing and Storing Dormant Bulbs
For bulbs that are to be lifted, the timing of excavation is crucial and must wait until the foliage is entirely dead. Once the leaves are brown and withered, the bulb has finished its energy storage for the season. The bulbs should be dug up gently, using a garden fork to avoid puncturing the bulb, which can introduce disease.
After lifting, excess soil should be brushed off, and any remaining dead foliage and roots can be trimmed away. Each bulb must be inspected carefully; any showing signs of damage, softness, or disease should be immediately discarded to prevent contamination. The next step is a short curing period, where the bulbs are allowed to dry for two days to a week. This drying should occur in a cool, dark, and well-ventilated area, such as a garage or basement.
Proper storage involves placing the cured bulbs in an environment that maintains a consistent temperature, ideally between 60 and 65°F. The storage container must allow for air circulation to prevent moisture buildup and fungal growth. Suitable options include mesh bags, paper bags, or cardboard boxes where the bulbs are layered with dry materials like peat moss or newspaper. This method ensures they remain dormant and viable until they are ready to be replanted in the autumn.