Tulip bulbs are a popular flower bulb that produces vibrant spring blooms. Many gardeners purchase tulip bulbs in the fall and store them over the winter before planting them in spring. This leads to the common question – how long can you store tulip bulbs before planting them? There are several factors that impact how long tulip bulbs will last when being stored unplanted. Read on to learn more about proper tulip bulb storage and what affects their longevity.
What are Tulip Bulbs?
Tulip bulbs are a type of flowering bulb that belongs to the Liliaceae family. The bulbs consist of a basal plate, protective skin-like scales called tunic, and a central disc that contains the embryonic flower.
Tulip bulbs go through a dormancy period every year. They require a period of cool temperatures between 35-48°F for 10-15 weeks to break dormancy and produce flowers. This physiological requirement means gardeners need to dig up and store bulbs over winter. The bulbs are then replanted in fall for blooms the following spring.
Proper Storage Conditions
To maximize how long tulip bulbs will last in storage there are some key conditions to provide:
Cool Temperatures
Tulip bulbs require cool temperatures between 35-48°F during their dormancy period. Storing bulbs at warmer temperatures can reduce their longevity. The cooler the temperature, the longer the bulbs will last. However, freezing temperatures can damage bulbs. An ideal storage temperature is around 45°F.
Good Air Circulation
Proper air circulation helps prevent mold growth and rotting. Storing bulbs in a breathable bag or crate allows air flow. Avoid storage containers that are fully sealed.
Low Humidity
High humidity encourages mold growth which can rot bulbs in storage. Try to keep humidity around 60% or less.
Dark Conditions
Tulip bulbs do not need light when dormant. Keep bulbs in complete darkness during storage. Exposure to light can sometimes initiate early sprouting.
| Storage Condition | Recommendation |
|---|---|
| Temperature | 35-48°F |
| Air circulation | Good airflow |
| Humidity | <60% |
| Light exposure | Complete darkness |
Ideal Storage Locations
Where is the best place to store tulip bulbs using the proper conditions above? Here are some ideal storage locations:
Refrigerator
A refrigerator set to around 45°F provides perfect cool, dark storage. Place bulbs in breathable packaging like paper or mesh bags. The low humidity in a refrigerator also helps prevent mold growth.
Unheated Basement or Garage
Any unheated, protected space that remains around 45°F makes a good storage spot. Providing air circulation and controlling humidity may take some added effort.
Outdoor Cold Frame
Burying bulbs under mulch or soil in a cold frame provides natural cold conditions. Just ensure the bulbs are protected from critters who may dig them up.
Commercial Cooler
Some professional growers store bulbs in commercial coolers. These provide precise temperature and humidity control.
Improper Storage Conditions
Storing bulbs improperly can significantly decrease their longevity and prevent sprouting. Here are some storage mistakes to avoid:
Excessive Heat
Temperatures above 60°F or rapid fluctuations in warmth can weaken bulbs in storage. Avoid warm locations like near hot water heaters or furnaces.
Excessive Cold
While tulip bulbs need cold conditions, freezing temperatures can severely damage bulbs. Allowing bulbs to freeze kills them.
Poor Ventilation
Stagnant, humid air encourages rotting. Make sure bulbs have air circulation during storage.
Sunlight Exposure
Light can confuse bulbs into early sprouting which uses up stored energy. Keep bulbs completely dark.
Pests & Rodents
Mice, squirrels or insects can feed on bulbs in storage. Use protective packaging and avoid easily accessible spaces.
Signs Bulbs Have Been Stored Too Long
How can you tell if tulip bulbs are no longer viable after long storage? Here are a few warning signs:
Soft, Squishy Bulbs
Tulip bulbs should feel firm. Soft, mushy bulbs mean rot has set in from excessive humidity or mold.
Shriveled, Light Bulbs
Severe dehydration also indicates bulbs are no longer sound. Healthy bulbs feel heavy for their size.
Cracked or Damaged Basal Plate
The basal plate on the flat bottom of bulbs sometimes cracks if bulbs have frozen or completely dried out.
No Roots or Shoot Formation
Viable bulbs will produce small white roots and a green shoot tip when sprouting.
Mold Growth
Signs of fuzz or mildew indicate rot from high humidity has damaged the bulbs.
How Long Tulip Bulbs Actually Last Stored Unplanted
Now that we’ve covered the ideal storage conditions for tulip bulbs and what can go wrong, how long can tulip bulbs actually last in storage?
Only One Season
Most experts recommend only storing tulip bulbs for one season – so from fall to the next spring. Tulip bulbs begin to deteriorate if kept dormant for longer than one year. Their ability to bloom diminishes.
Up to 2 Years Max
Under absolutely perfect conditions, some tulip bulbs may last up to 2 years in storage. However, the bloom rate and quality deteriorates dramatically the second year.
Species Tulips Last Longest
Botanical species tulips like Tulipa kaufmanniana tend to store slightly longer than hybrid tulips. But even species tulips should ideally only be stored one season.
Store Properly After Forcing
Tulip bulbs that were previously forced for winter blooms indoors also have a shortened storage life. They may only last a few months after forcing before deteriorating.
Maximizing Tulip Bulb Longevity
Want your tulip bulbs to last as long as possible when stored? Here are some key tips:
Start With Top Quality Bulbs
Buy large, firm bulbs from a reputable source. Avoid damaged, soft or sprouted bulbs.
Discard Any Damaged Bulbs
Inspect bulbs carefully and remove any that show signs of rot or damage before storing. Just a few rotting bulbs can spread mold to healthy bulbs in storage.
Allow Bulbs To Cure
After digging up bulbs in fall, allow them to cure in a warm, dry spot for 1-2 weeks. This dries them out and seals injuries from digging.
Clean Off Excess Soil
Gently remove excess dirt from bulbs but be careful not to damage the protective tunic. Clean bulbs store better.
Use Breathable Packaging
Wrap bulbs loosely in paper or mesh bags. Tight plastic encourages condensation and mold.
Check Bulbs Occasionally
Check for any signs of rotting during storage like mold, softness or shriveling. Remove affected bulbs immediately.
Conclusion
Tulip bulbs can only be stored unplanted for a limited time. While most only last one season, you can potentially get 2 years of bloom time with perfect storage conditions. Keep bulbs cool, dry, and pest free in breathable packaging to maximize longevity. Avoid damaged bulbs and improper storage that allows rotting. With proper care, you can successfully store bulbs and enjoy their vibrant blooms the following spring.
