Week of March 13, 2022 – March 19, 2022
by Bridget Jones, Environmental Educator
As the snow begins to melt and days get longer, I’ve been looking forward to seeing leaves start to emerge on the trees at Baltimore Woods. Right now, weeks away from the leaves’ emergence, the trees look as still and silent as they have all winter. But at the tips of their branches, tiny buds have begun a rush of activity to prepare for the coming spring. At this time of year, these buds may catch our eye. Some begin to grow or change color to signal their spring preparations. What is behind these changes? What happens inside a tree bud in early spring? To find the answer to this question, we have to think back a few seasons.
Trees start to form buds in the summer and fall, before the cold of winter sets in. During the milder weather, they pack nutrients and sugars into the buds. Many cover them with a scaly protective coating to guard against the elements. Throughout winter, while birds and squirrels search for food among their branches and humans shovel snow beneath them, these buds wait for spring. They track the temperature, keeping count of how much time is spent above the freezing mark. Then, when warmer weather arrives, growth is set in motion. Nutrients and sugars kept in storage are sent towards the new growth. Inside the bud, new leaves start to grow. Eventually, the buds burst open, revealing the first leaves of spring.
During winter’s transition into spring, it can be easy to wish for green leaves to emerge sooner. But by taking a closer look at leaf buds, we can appreciate a subtler change that signals the arrival of warmer weather. Over the next few weeks, see if you can notice the buds on trees in your neighborhood beginning to change. Which trees show the earliest growth?