Storing bulbs may be essential to ensure healthy flowers in the following growing season. For example, tulips (Tulipa spp.) are hardy in U.S. Department of Agriculture plant hardiness zones 3 through 8 and require a chilling period to produce flowers every spring. Storing bulbs improperly may end with the tulips dried out and not able to resprout in spring.
On the other hand, gladiolus (Gladiolus spp.) prefer USDA zones 7 through 10 and need to be dug up and stored for the winter in colder climates. If you find any dried-out bulbs, you may be able to rehydrate them for replanting in the garden bed.
Determine If the Bulb Is Alive
When you find those bulbs – perhaps still in the bag, under a counter or in the garage – check to see if they're still viable. Press the bulb gently between your fingers. If it is easily crushed and crumbles, it's only good for the compost pile. If it still has a firm core, you may be able to save it.
Sometimes, bulbs begin to sprout in storage. If the shoots are green or greenish and not dried out and the bulb feels solid, you can attempt to rehydrate the bulb before planting it in the garden or flowerpots.
If the bulbs are slimy and rotting, discard them in the trash. Whether it happened from improper storage or they were infected by a fungal disease, you shouldn't attempt to save the bulbs. They could spread diseases to the garden bed and your other flowers and bulbs.
Rehydrate the Bulbs
Put on gloves and safety goggles to protect your hands and eyes. Wash a bucket using dishwashing liquid. Rinse well and then sterilize it by soaking it in a solution of one part bleach to 10 parts water for 15 minutes. Rinse and allow it to air dry. Fill the bucket with lukewarm water and add the bulbs. Soak them for at least two and no more than 12 hours to rehydrate the bulbs.
Another method of rehydrating shriveled but still viable bulbs, corms, rhizomes and tubers is to place them in moist sand or peat moss for several days. Check them daily and mist them if necessary to keep the medium moist but not waterlogged.
Remove the bulbs and plant them immediately in a well-drained garden bed amended with 2 to 4 inches of compost and well-decomposed manure. Keep the bulb bed evenly moist but not waterlogged during the growing season. Alternatively, plant the bulbs in flowerpots and place them in a sunny window or on the patio.
Store After the Growing Season
When the foliage dies back, dig up your bulbs for storage. Most tulip bulbs need chilling in order to bloom in spring, while gladiolus need protection from winter's freezing temperatures.
Carefully dig up the bulbs and wash off the soil. Allow them to dry for one to three days. In the case of tulips, daffodils (Narcissus spp., zones 3-9) and other bulbs that require winter chilling, put the bulbs in clearly labeled bags or a cardboard box and place them in the refrigerator for 12 to 16 weeks. Keep the bulbs away from apples and other fruits because apples produce ethylene gas, which affects the bulbs' ability to bloom in spring.
When storing tender bulbs for the winter, wash them and allow them to dry. Then, place them in one or two layers in a container filled with slightly moistened peat moss or sawdust. Check them every few weeks and mist if necessary to moisten the gladiolus bulbs. Dried-out bulbs won't sprout when replanted. Store them in a dark location in a shed or garage where temperatures remain above freezing.
Plant Winter-Flowering Bulbs
While many bulbs flower in late spring, summer and fall, there are a few winter-flowering bulbs, rhizomes and tubers that rise from the frozen soil in late winter and early spring. Hardy winter- and spring-flowering bulbs are planted in late summer and early fall in a well-drained flower bed. Among the bulbs to plant in fall are hardy cyclamen (Cyclamen coum, zones 4 through 8), Lenten roses (Helleborus x hybridus, zones 6 through 9), snowdrops (Galanthus nivalis, zones 3 through 8) and winter aconite (Eranthis hyemalis, zones 4 through 7).
- Missouri Botanical Garden: Tulipa (Group)
- Pacific Bulb Society: How To Grow Bulbs
- University of Maryland Extension: Bulbs
- UC Master Gardeners of Butte County: Plant Cyclamen and Hellebores for Winter Color in the Garden
- Wisconsin Horticulture Division of Extension: Winter Aconite, Eranthis Hyemalis
- Longfield Gardens: All About Gladiolus