Comparing fresh and dried leaves is an observation-over-time activity that teaches one of science's most important practices: noticing change. Children collect fresh leaves, observe and document their properties (color, flexibility, weight, smell), then check again after one week of drying. The changes are dramatic and prompt genuine questions: Why did the leaf get smaller? Why did it change color? Why is it crinkly? These questions open windows into plant biology that lead naturally into discussions of cells, water, and photosynthesis.

Setup

1. Collect several identical leaves (same tree, same size if possible).
2. Observe and document fresh leaf properties: color, flexibility (bend without breaking?), size (trace on paper), smell (scratch surface), texture, weight (place on a simple balance).
3. Place one set of leaves in a book or flower press to dry flat; leave another set on a tray exposed to air.
4. Observe after 3 days, 7 days, and 14 days.
5. Compare: what changed? What stayed the same?

What Changes and Why

• Color: Green chlorophyll breaks down as cells die, revealing underlying yellow and orange pigments.
• Size: Leaves shrink as water evaporates from their cells.
• Flexibility: Dried leaves become brittle because the water that kept cells plump is gone.
• Weight: Significantly lighter — most of a leaf's weight is water.
• Smell: Fades as volatile aromatic compounds evaporate with the water.

Frequently Asked Questions

What types of leaves dry most interestingly?

Large, flat leaves with prominent veins show the drying process most clearly and make excellent nature journal drawings. Autumn leaves that are beginning to change color show the most dramatic color transformation as they dry. Aromatic leaves (bay laurel, mint, rosemary) demonstrate the change in scent most noticeably. Avoid very thin, delicate leaves that disintegrate quickly; oak, maple, and horse chestnut hold up well through the drying process.

Related science: Grow Grass in a Cup | What Dissolves in Water | Bark Texture Rubbings