Why do gum trees drop their bark?
Quick answer from Eartha
Gum trees shed their old bark to make room for growing! As the trunk grows wider underneath, the outer bark can't stretch, so it peels away in curly strips or big flaky sheets. This also helps get rid of insects, moss or lichen living on the old bark. Underneath is fresh, smooth new bark.
The longer story
Gum trees, also called eucalypts, are famous for their peeling bark, and Australia has hundreds of different eucalyptus species. Many of them shed bark every year, usually in summer.
As a tree trunk grows thicker, the tough outer bark can't stretch to fit. So instead of splitting messily, many gum trees simply let the old outer layer peel away in ribbons, curls or flaky patches.
Shedding bark also helps the tree stay healthy. Insects, moss and lichen that have settled on the old bark get shed along with it, giving the trunk a fresh start.
Underneath the old bark is often smooth, colourful new bark, sometimes cream, pink or grey. That's why you can find beautiful, patchy trunks on gum trees all over Australia.
Try this at home: bark rubbing
- Find a gum tree with peeling bark nearby.
- Hold a sheet of paper against the trunk and rub a crayon sideways over it.
- Look at the pattern the bark left behind.
Words to know
- Eucalypt
- Another name for a gum tree, common across Australia.
- Bark
- The tough outer layer that protects a tree's trunk.
- Lichen
- A tiny crusty living thing that can grow on tree bark.
For grown-ups: what is my child learning here?
Age band: 5-8
Curriculum link: Australian Curriculum v9 Science, AC9S2U01
The concept: Australian plants have distinctive features, such as bark shedding, suited to their environment.
More classroom ideas are on our teachers page, and safety notes for families are on for parents.
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