California isn’t typically known or recognized for its fall foliage. If you’ve been to Vermont and the Northeast U.S., you’ll understand why people seem a little jaded when it comes to the colors red, yellow, orange and green. Nature puts on one amazing spread each fall season, providing a favorite travel time for what’s known as leaf peeping (watching the fall foliage colors.) California has its own fall foliage to see, and for those with an appreciation of nature, our leaf peeping season is spectacular, especially in the Sierra Nevada mountains. What weather is needed for good color? The best autumn colors occur under clear, dry, and cool conditions but not freezing weather.
In a process in which leaves turn green each spring as they use pigments (chlorophyll, xanthophyll, and carotenoids) to harness the sun’s energy, as temperatures cool and days get shorter, leaves on deciduous trees stop producing new chlorophyll, and the familiar green color breaks down to reveal the other pigments that have been masked all season. Chlorophyll is expensive to make (for the tree); so when there isn’t enough light to make it worth expending energy on, the green fades and the colors beneath show.
What Colors Do Leaves Change to in a Variety of Yosemite's Tree Species?
Quaking aspen: Yellow
Non-native sugar maple: Red
Bigleaf maple: Bright Yellow
Black oak: Orange/brown to golden yellow
Ceanothus/Deer brush: Yellow
White alder: Yellow
Black cottonwood/Fremont cottonwood: Yellow
Poison oak: Red to purple