Well, things have certainly cooled down! We're starting to get a blush on the few trees and shrubs that exhibit fall color here in warm-winter SoCal. (Sorry all you transplants that long for forests of gold and orange - go grab an orange off your backyard tree in January and try to remember what it was like to de-ice your car in the mornings!) We do have a few outstanding groves for fall color. The one that comes to my mind are the gingko trees planted near the north entrance of the Huntington in San Marino (on Allan and Lombardy Streets). Do you have a favorite deciduous tree? Or a favorite evergreen tree that says "winter is here" in SoCal?
In mid to late fall, I love our Southern California Black Walnuts where they co-exist with the (evergreen) Toyon. The Walnuts are turning a bright, golden yellow and making an exquisite companion to the green leaves and red berries of the Toyon. Notice this combination when you drive the canyons, especially in the Santa Monicas. ---But if the question is about favorite "winter" tree, then give me those wonderful Chinese magnolias who finally drop all those burnt brown leaves (ugh), revealing silvery trunks and stems, soon to be decorated with either white star shaped flowers (Magnolia stellata), or pink, white, or purple cup shaped flowers (M. soulangiana).
What a great observation, Kathryn! I never thought about CA walnuts for fall color, but of course they look great right now, especially mixed with Toyon.
It seems like the Chinese magnolias are blooming earlier every year - I think I've seen them blooming in January now.