Winter. Far from simply being a season that temperate-growing plants must adapt to, the deep chill of those long and dreary months are actually required by some plant species in order for for them to flower or even produce leaves. This is a process known as vernalization. It is easy to see how this may have evolved in different plant species. It makes no sense to bloom randomly or to grow when the world is blanketed with snow. In order to reproduce successfully, individuals of a species need to time their growth and their blooms so that they all happen together during the correct season. Whereas some species of plant tune into the relative lengths of day and night, others utilize temperatures to synchronize their life cycles. Many of our spring ephemerals require such vernalization in order to flower. What’s more, winter dormancy gives plants a much needed rest. Attempting to force a perennial to grow year round would cause the plant to quickly burn out and die. So, as you hunker down for the long winter months to come, you can rest easy knowing that the cold temperatures outside are doing your beloved plants some good.