The russet and golden colors of autumn are magnificent this time of year brightening our gardens one last time before winter takes hold.
But why exactly do leaves change color? The short answer is we are witnessing the withdrawal of chlorophyll – the green pigment in leaves that facilitates photosynthesis whereby plants make their own food from sunlight.
As the days shorten and temperatures drop plants respond by ceasing photosynthesis to prepare for winter dormancy. The chlorophyll breaks down exposing the other color pigments that are actually always present in the leaf but that are concealed to our eyes by the green. This process reveals the earthy tones of yellows, oranges, and browns while other complex chemical reactions produces the reds and sometimes purples.
At the same time, specialize cells begin severing the tissues that connect the leaf stem to the branch. This causes the leaf to fall and us gardeners to start looking for our rakes!
Are you preparing for fall garden tasks? See our Fall Gardening Checklist for tips.