Why do leaves change colour?
Various pigments in the leaves cause the spectacular colours you see around Sheffield Park. Green comes from chlorophyll, needed to convert sunlight into food for the plant. Orange and yellow come from carotenoids which are present in the leaves all year but are normally hidden by chlorophyll. Reds and purples come from anthocyanins which are produced towards the end of summer. The chemical changes affect species in the garden in different ways, producing the wide range of colours on display.