After summer's scorching heat, autumn's cooler temps signal it's time to plant spring-blooming bulbs. They may not offer instant gratification, but with minimal effort, fall-planted bulbs will provide vibrant post-winter blooms well worth the wait.
Spring-blooming bulbs have a unique growth cycle. They establish roots in the fall, spend winter underground, sprout and bloom in the spring and then go dormant in early summer.
Because most hardy fall-planted bulbs, including tulips, crocus, muscari, hyacinths and alliums, originate from climates with cold winters, they require chilling out for 10 to 13 weeks in temperatures below 40 degrees to bloom properly in the spring. This dormant period allows fall bulbs to establish a deep robust root system before sprouting foliage and flowers. The ground will become consistently cold over the winter to offer the bulbs plenty of the chill time they'll need to ready themselves for a burst of spring blooms.
The dormancy begins as the weather grows colder and the days grow shorter. Once planted, bulbs start producing roots that absorb water and nutrients from the soil. While the soil insulates and protects the bulbs from frost damage, the cold temperature triggers a biochemical response that stimulates flower formation and root growth. The bulb's natural internal timer then begins counting down until it's time for its spring bloom.
Gardeners in regions with cold winters (zones 4 to 7) can begin planting spring-flowering bulbs as soon as the ground cools and when evening temperatures average 40 to 50 degrees. As a rule of thumb, planting should start at least 6 to 8 weeks before the ground freezes, but not too early or they'll sprout and may suffer frostbite. (Consult this frost date
Read more on burpee.com