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Counting a young white pine's age by its branch whorls

All year

On a young eastern white pine, the branches come out in rings called whorls, one ring for each year of upward growth. Count the rings up the trunk to estimate the tree's age, and check that the needles grow in bundles of five.

Why this time of year

Any day of the year works, because white pine keeps its needles and its branch tiers through every season.

How to notice it

  1. Find a young white pine, one short enough that you can see its whole trunk, with soft bluish-green needles and branches sticking out level.
  2. Stand back and look for rings of branches around the trunk at the same height. Count each ring from the bottom stub or knot up to the top.
  3. Look at the space between one ring and the next. Are the gaps all the same?
  4. Look closely at one needle bundle, or pick up a fallen one, and count the needles: white pine has five.

Try this with kids: How many rings of branches can you count on this tree?

Word to know: A “whorl” is a ring of branches that all grow out of the trunk at about the same height.

Safety

  • Do not climb the tree. Count from the ground.
  • Look for sap on branches and trunks and keep it off clothes and hands.

Sources

  • dnr.state.mn.usMinnesota DNR: 'On young trees, branches extend horizontally in whorls, marking successive years of upward growth.' Needles 'grouped in bundles of five', bluish green; 'In forested areas, lower branches often fall away'.
  • bugwoodcloud.orgKim D. Coder, University of Georgia Warnell School, 2021: 'Crown form is tied to the tiers or whorls of branches produced each year.' 'Pinus strobus needles are 2.7 - 5 inches long with 5 needles per bundle.'
  • naturalresources.extension.iastate.eduIowa State Extension: 'Its leaves or needles occur in bundles or fascicles of five, 3-5 inches long'; limb length varies from one whorl to the next.
  • herrontownwoods.orgHerrontown Woods (nonprofit, corroboration only): 'Calculate the age of a white pine by counting the whorls of branches on the trunk-one whorl per year.'

Checked against these sources on September 29, 2026.

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