Tulip bulbs are generally planted in the fall according to package directions and U.S. Department of Agriculture plant hardiness zones. In areas such as zones 8 to 10, where freezing temperatures are rare, bulbs may be stored in a refrigerator six to eight weeks before planting for successful spring flowering.
Planted tulip bulbs should be protected with mulch during the cold winter months in zones 4 through 7, where temperatures reach extreme lows. A light mulch is more appropriate in some areas, as excess warmth may trigger premature growth.
Tulip bulbs can be chilled before planting them in pots to force them to bloom off cycle. Container tulips should be placed outdoors in mild temperature regions after the danger of a freeze has passed. Containers that are placed indoors on a sunny window sill in colder areas will grow and bloom in the spring.