By Mary-Jane Pilgrim, Master Gardener
In the heart of downtown Selwyn where a heavy winter blanket covers my gardens, a magical process is unfolding in the underworld of some of my plants.
In the heart of my living room, I’m actively crossing off the days until Spring.
But, back to the plants. To monitor the seasonal progression and to time their reproductive development, plants must be able to sense and remember environmental cues such as temperature. The process by which plants use a prolonged cold period – winter – to promote flowering is known as vernalization.
Vernalization is the botanical equivalent of a winter sleepover, but instead of cozying up with blankets and hot cocoa, plants snuggle up to the cold. This process is essential for plants like winter wheat, rye, and most spring flowering bulbs in our region. Basically it is a cold period where specific plants not only go dormant (they hit the pause button until the weather warms) but must be exposed to a certain number of days with minimum temperatures or they will not grow properly and flower. It acts as a sort of safety mechanism to ensure that the growing and blooming process takes place at the correct time.

Picture this: a seed or bulb lies dormant in the frozen soil, patiently waiting for winter’s icy touch. As the temperature drops, the plant detects the chill and starts a biochemical countdown for a certain number of days. It’s as if the cold serves as a bell ringer, signaling that it’s time to prepare for the grand spectacle of spring. It’s amazing that even in the harshest conditions, nature has its own way of orchestrating the grand spectacle of life.
So, in my living room I continue to mark the winter days off one by one, reminding myself that the bulbs I planted in October need a cold cold winter to make my garden spring to life. It will definitely be worth it!