Life of a Tree

Children will explore the life of a tree.

Lesson Objective

Children will explore the life of a tree using a cross-section slice of a tree (a tree cookie).


What You'll Need

  • Tree cookie (real, if available, or a digital image from an Internet search)
  • Paper plates – 1 per child
  • Brown, green, and black crayons – 1 per child
  • Red cut-out heart shapes – 1 per child (or use stickers)
  • Glue sticks

What To Do

  1. Display the tree cookie, and explain that it is a sliced section of a tree.
  2. Discuss the bark (exterior), the ring next to the bark (cambium), and center circle (heartwood) of the tree (see Did You Know?).
  3. Discuss the rings of the tree cookie, and explain that one ring is equal to 1 year of a tree’s life.
  4. Have the children help count the rings.
  5. Tell the children that they will be making a tree cookie with the same number of rings as their age.
  6. Distribute the paper plates and brown crayons.
  7. Have the children color the bumpy edge of the plate with the brown crayon to represent the bark.
  8. Distribute the green crayons, and have the children draw a green circle around the inside of the bark to represent the cambium.
  9. Distribute the heart shapes and glue sticks. Have the children glue a heart in the center of their plate to represent the heartwood.
  10. Distribute the black crayons, and have the children draw rings around the heart. Tell them to draw the same number of rings as their age.

Guiding Student Inquiry

  • Describe what you see in the tree cookie.
  • What do you think the bark does for the tree?
  • What do you think trees are used for?
  • Explain how you know the age of the tree.

Explore, Extend & Integrate

  • Have your class adopt a tree outside. Have the children measure the tree by counting how many children, with hands joined, it takes to go around the tree. Have them observe any animals that may live in the tree. Measure the tree. If the tree is large, measure the tree by seeing how many children it takes to go around the tree. If the tree is small, have the children measure it using a measuring tape or piece of ribbon. Take pictures of the tree throughout the year so the children can see how it changes over time. The children can draw pictures of the tree to keep a journal of the changes.
  • Discuss the parts of a tree: the roots, trunk, branches, leaves, needles, cones, nuts, fruit, and bark. Display pictures of different types of trees, such as pine trees, fruit trees, nut trees, and hardwood trees. Make a chart of the items that each of these trees have in common and which tree types the other parts belong with.

Check for Children’s Understanding

  • Could children describe the tree cookie as having rings?
  • Could children explain that the bark protects the tree?
  • Could children tell that trees are good for shade and provide shelter for birds, animals, and insects?
  • Could children explain that each ring in the tree cookie is 1 year of a tree’s life?


Did You Know?

A tree cookie is a horizontal cross-section of a tree that shows the interior structure of the tree. The outside of the cookie is covered by bark, which protects the tree. Next to the bark is a ring called the cambium, which helps the tree make new bark. The center of the tree cookie is called the heartwood, and it supports the tree on the inside. The rings around the heartwood indicate the age of the tree; one ring is equal to 1 year of the tree’s life.

Trees are important to people and nature. Trees provide oxygen, shade, wood, and paper. Many animals spend much of their lives in trees. Trees also provide shelter from weather and protection from enemies for many animals. Trees provide food in the form of fruits, nuts, leaves, bark, and roots. Even dead trees provide shelter and food for many insects.

Vocabulary: Child-Friendly Definitions

  • tree cookie – the cross-section of a tree trunk that shows the many different layers of a tree.
  • bark – the outside covering of a tree.
  • cambium – a thin layer between the bark and wood of a tree that helps the tree make new bark.
  • heartwood – the center part of a tree.
  • ring – a layer of wood made by a tree in a single year.
  • age – how old something is.

Lesson Tips

  • Try to choose an image (or the real thing) that clearly shows the interior structure of the tree, so the children can easily see the bark, cambium, and heartwood and can count the rings.


  • A Tree Is Nice by Janice May Udry
  • Be a Friend to Trees by Patricia Lauber
  • The Seasons of Arnold’s Apple Tree by Gail Gibbons
  • The Great Kapok Tree: A Tale of the Amazon Rain Forest by Lynne Cherry
  • A Grand Old Tree by Mary Newell Depalma

Home School Resources

Home educators: use these printable lesson PDFs to teach this lesson to your home schoolers. They're available in English and Spanish.

Home/School Connections

Las Conexiones a la Casa

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Content Provided By

Common Core State Standards Initiative – These lessons are aligned with the Common Core State Standards ("CCSS"). The CCSS provide a consistent, clear understanding of the concepts and skills children are expected to learn and guide teachers to provide their students with opportunities to gain these important skills and foundational knowledge [1]. Visit the CCSS