A green canopy becoming gold or red can transform an ordinary walk. The change begins inside the leaves, as deciduous trees prepare for winter. Their colour is a clue to a seasonal process, rather than a coat of colour added from outside.

The green pigment fades

During the growing season, chlorophyll helps leaves capture light for photosynthesis and gives them their familiar green appearance. As autumn advances, chlorophyll breaks down. Yellow and orange carotenoid pigments, already present but less visible beneath the green, become easier to see. Woodland Trust’s Nature’s Calendar explains this change.

Red has a different story

Not every autumn colour was hidden in the leaf all summer. Some leaves produce anthocyanins during autumn, adding red and purple tones. The display therefore reflects both the loss of one pigment and, in some leaves, the production of another. Tree species, conditions and timing help explain why one tree turns bright red while its neighbour looks yellow or brown. Woodland Trust describes the pigments and weather behind autumn colour.

A quieter way to watch autumn

Choose a tree you pass regularly and look at it again over the following weeks. Note when the first leaves change, when the colour spreads, and when leaves begin to fall. A familiar place can become an ongoing observation rather than a single photograph. Nature’s Calendar records these seasonal stages to help track the timing of autumn.

A woodland does not change all at once. Watching that uneven transition gives us time to notice individual trees and the season unfolding around them.

Sources & further reading