Question: Can you explain why some shrubs bloom so early in spring that their flowers are sometimes damaged by late freezes? What's the point, besides cheering up the winter-weary gardener?
Answer: Early-blooming trees and shrubs—such as winter hazels, daphnes, wintersweet, forsythia, Cornelian cherry, winter jasmine and heaths—bloom so early that their blossoms are sometimes damaged by late freezes. What possible benefit could come from unfurling one's buds when snow and ice are still possible? The answer is that pollinators pay them special attention. By blooming in advance of the spring rush, winter-blooming trees and shrubs get immediate service. On any day or night when the temperature is above freezing, insects are out and about. The resulting gain in fertility for early bloomers outweighs their periodic losses from cold damage.
For the insects, too, there are benefits to a life lived out-of-season. The night-flying owlet moths that pollinate native witch hazels, for example, enjoy a bat-free existence. (Bats, so abundant on summer evenings, spend their winters hibernating in caves.)