As the last asters of the year are wrapping up their flower display and monarchs are migrating through to more southern latitudes, spring flowers aren’t always at the center of attention for most gardeners. However, now is the time to set the stage for some of the most beautiful and early blooms of spring.
Fall is actually the ideal time to plant spring flowering bulbs. These amazing plant structures are tiny powerhouses of energy that can be planted now to explode with flowers and foliage as spring temperatures awaken them next year.
While warming early spring weather triggers their awakening, the winter’s cold is actually an essential part of their life process as well. Hardy spring flowering bulbs require a chilling period, typically around 10 or 12 weeks at temperatures between 32°F and 45°F, in order to initiate growth in spring. This chilling requirement is simply part of the dormancy process for plants that are cold hardy perennials.
Dormancy is an incredible adaptation that allows plants to shut down and weather harsh times, like the wintertime, when either cold temperatures or lack of water create near impossible growing conditions. Plants have a variety of ways to ride out the winter weather. Woody plants simply shut down their processes, with deciduous species dropping their leaves entirely. Whereas most herbaceous species die back to the ground with their roots nicely protected in the soil and ready to initiate growth in spring. Bulbs are simply a modified stem structure that stores energy and protects the future flower bud until spring.
The chill requirement for all these plants sets the length of their dormancy and is slightly different for all depending on when they initiate growth in spring. It prevents early growth during a warm snap in January and helps time spring flowers with the emergence of pollinators.
Spring flowering bulbs emerge in early spring, complete their active growth by early or mid summer and dieback to the ground, entering dormancy. This allows these plants to avoid the harsh summer conditions, with high heat and low moisture, as well as to capitalize on full sun in early spring, prior to leaf out of woody plants. So, their dormant period is much longer than just winter, but does require exposure to the winter’s cold.
With this unique window of growth during the early spring, these bulbs offer an equally unique floral resource for pollinators during a time of few options. They can provide a very important food source for pollinators that emerge early in the growing season when many gardens still lie dormant and offer little pollinator value.
However, most of these bulb plants are non-natives and we all know that natives provide the best support for pollinators. Since native plants have a coevolutionary relationship with native pollinators, they offer more than just floral resources and often support leaf-feeding larvae, overwintering adults and other aspects of the insect life cycle.
While I am a huge proponent of planting native, I still value non-native plants that help to extend the season of blooms my garden can offer. Non-natives are a great option for filling a void in flowering times, not only for pollinator value, but also for added ornamental beauty.
With their unique growing season, spring flowering bulbs can very easily be integrated into most any garden space. They emerge much earlier than most perennials and rarely compete since their annual growth is winding down about the time most perennials are just starting to really get going. Therefore, bulbs can be planted in a more naturalized arrangement by tucking them in around existing perennials throughout your garden. Consider adding them individually or in small groupings around larger perennials that emerge later and will fill the space as bulb plants dieback. Or, many folks do solid plantings of tulips, daffodils or other bulbs for a huge splash of spring color if you have the space.
This fall, consider the spring buzz of pollinators and add some bulbs to your garden spaces now. It’s a great way to finish out the gardening season and set the stage for spring blooms.