Yellow leaves can be an ambiguous symptom in plants. Like a fever in humans, yellowing leaves often indicate a health problem, but there are so many causes that the symptom doesn't indicate exactly ...

Why do some leaves turn yellow in autumn, while others turn red? • Leaves contain various coloured pigments. The pigments carotene (orange), xanthophyll (yellow) and chlorophyll (green) are found in ...

I recently answered a question in my advice column on some azaleas with leaves turning color. A significant percentage of the leaves had turned orange, and the gardener was concerned that something ...

This is the time of year when Nicole Hughes gets constantly distracted by the fall foliage as she drives around North Carolina. "I'm always looking," says Hughes, a biologist at High Point University.