Emerging Bulbs and Cold Weather

UNH Cooperative Extension Info Line Question of the Week

Q. The daffodils next to my house are up about 2 inches. Will more snow damage them?

A. It’s fairly common during brief warming periods in winter for spring-flowering bulbs to send up a couple inches of foliage, especially if they are located next to a building in a warm, protected location. This phenonenom is most common with bulbs such as tulips, daffodils and crocus. It is usually not a problem.  Temperatures drop again, snow eventually comes to cover the foliage and the foliage stops growing.  Occasionally, if we get extreme cold before the foliage is covered by snow, the foliage will “burn” or turn yellow.

Unless we have an unusually warm winter, flower buds will remain protected inside the bulb underground.  If we get an extended period of early warm weather, flower buds can emerge.  If those flower buds are nipped by extreme cold, they may not bloom this spring, but the bulb underground will survive and come back to bloom next year.

There’s not much you can do to keep nature from taking its course, but it might help to cover your bulbs with 2 to 3 inches of mulch, after several successive days of cold temperatures.  Once the soil is frozen again, mulch will help keep your bulbs dormant. Mulching over plants when the weather is warm may actually encourage growth by helping to keep the soil warm.

Jeremy DeLisle is the program coordinator for the UNH Cooperative Extension Education Center. The center answers questions about gardening and more at answers@unh.edu, or by calling (877) 398-4769 Monday through Friday, between 9 a.m. and 2 p.m.