Opening Leaves

In New York State, May is the month that trees get new leaves. The change from the bare branches of winter to the leafy shade of summer will give us a very different looking world to enjoy. What can we learn this month about this wonderful change?


Look around your school or home. Is there a tree that has been standing without leaves this winter that you could visit easily? Could you go to look at it every day, or nearly every day? Choose at least one tree with branches you can easily reach and observe as its leaves open this month. If some trees have already started to leaf out and others have not, choose one that hasn't changed too much yet.

When you visit your tree, look carefully at the buds. Make a small pencil drawing of one small branch and its buds. Look at the buds with a magnifying glass. Make another drawing a day or two later. Keep returning and drawing any changes that you see. Is there a way you could measure the changes you are observing?

There is a fancy word for the way leaves are arranged inside a bud; vernation. As a leaf bud  opens you can see a tiny leaf inside and watch as it opens up over one or more days. Some leaves look like tiny accordion fans unfolding. Some leaves unroll. Watch closely as the leaves of your tree open. Draw or photgraph what you see. How would you descrbe this to someone who has not seen it? Do they unfold, unroll, uncurl? Are there flowers in your tree's buds?

Observe the leaves as they get larger. Does their color change at all? Is there more than one leaf in a bud? Do any insects visit your tree's leaves? How do you know?

The trees that lose all their leaves before winter and then replace them in the spring are called deciduous trees. Evergreens will also be growing new leaves in the spring. It might be interesting to observe leaves growing on an evergreen tree too.

As you make your observations, what questions do you have? How can you find answers? Making observations, raising questions, figuring out ways to answer your own questions, this is how science works to understand the universe around us.

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