Winter Twigs

If you have a magnifying glass or hand lens you can explore a wonderful world hidden to most people, the world of the miniature. You don't have to wait for warm days to get started; just take a look at the branches of the nearest tree or shrub.

Find the bud at the end of a branch. Did you know that trees and shrubs have their buds for next year's leaves already there in the winter? They grow them in the late summer when there is plenty of sunlight to help them make food to grow the tiny leaves that are locked up in most buds.

Look closely at a bud. Is it covered with little pieces that look a bit like fish scales or roof shingles? These are called bud scales. They make a covering for the bud to protect what is inside. Look at buds on different trees and shrubs. Are they all the same color? Are they all the same shape? Are they all the same size? Do they all have the same number of scales?

When the buds start to open and grow in the spring, the scales will fall off. This will leave marks in the bark of the growing branch. You can find the scars from last year's buds if you know where to look. Start at the last bud at the end of a branch (it's official name is the end bud or terminal bud) and move slowly towards the trunk of the tree. Stop when you see some small marks in the bark of the branch that go right around the branch. These are the scars of the scales that covered last year's end bud. The distance from these scars to the end bud shows how much the tree branch grew last summer. Did it grow very much? This newest growth of the branch, from last year's end bud scars to this year's end bud, is called a twig. 

Sometimes you can find another set of these scars by moving farther along the branch towards the tree trunk. These are the scars from the end bud scales that opened the spring before last. They show how much the branch grew that summer. On trees with smooth bark like magnolias and beeches you can find year after year of end bud scars. Count them to figure out how old the branch is. On most trees, the scars become too hard to find after a couple of years.

Most twigs have more than one bud. Some buds grow from the side of the twig or branch. The fancy name for these buds is lateral buds. It means side buds. Each one will have a scar right next to it where a leaf was last summer. Look at these leaf scars with your magnifying lens. Can you see small marks inside of them? These are where veins went from the twig into the stem of the leaf. The veins carried water into the leaf so it could be used to make food. They also carried food made in the leaf out into the twig to be sent to feed the rest of the tree or shrub. The official name for these marks is bundle scars.

Different kinds of trees and shrubs have buds and leaf scars that look different. They can help you figure out what kind of tree you are looking at. Sometimes the leaf scar with its bundle scars inside can look like a little face. Look at different trees and shrubs to see what the leaf scars look like.

To learn more about winter twigs and to see some photos of twigs with their buds and scars, visit one of these websites: 

The Winter Tree Identification site has a whole key to use to find out what kind of tree you are looking at or you can just click links for photos and the definition of terms.

Visit the Know Your Trees site from Cornell University. This site provides a guide for identifying New York State trees.

Virginia Tech has an online identification key with good pictures.

The College of Natural Resources at Virginia Polytech has information about Twigs. Visit their Identification Fact Sheets to see more photos of twigs. 

And most importantly, go outside and look at some trees and shrubs! There are many interesting details to notice.
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