It may still feel like summer, but autumn officially arrived on September 22, at 6:30 a.m. The fall equinox marks the moment when the Sun crosses the celestial equator, the imaginary north-south line that divides the Earth into two hemispheres. 

Equinox, meaning “equal nights,” occurs twice a year, in spring and fall, when day and night are of approximately equal length. 

From now until the Winter solstice on December 21, the sun will rise and set increasingly farther south each day, bringing shorter days, but also the potential for increasingly spectacular fall and winter sunsets, and the clearest dark skies for sky watching.

This is also the season of fall color, even in the Santa Monica Mountains, where winters are mild. This area usually reaches its peak autumn colors in December, but fall color is beginning to appear in gardens and throughout the mountains.

Just like its close relative poison oak, skunkbush turns scarlet and even hot pink in the autumn, but unlike its toxic relative, this plant doesn’t cause skin irritation.
It’s not a plant that anyone welcomes in their garden or along the trail, but poison oak is one of the most beautiful and reliable sources of autumn color in the Santa Monica Mountains—just don’t get too close!

It may seem counterintuitive, but the earliest color is often at the bottom of the canyons, not the mountain tops. Plants that grow in the riparian zone deep in sheltered canyons are also more likely to be deciduous than the tough evergreens of the chaparral. Cold air drainage contributes to the earlier fall color in these areas. Cool air is heavier than warm air, and when conditions are right and there isn’t any wind, it sinks, draining down gullies and canyons like water. This is a place to look for the living gold of willows, cottonwoods, and sycamores, and the vivid reds of poison oak and its close relative Rhus trilobata, or skunkbush.

Garden plants offer some of the best local color. Mulberry trees and ginkgo biloba are reliable sources of autumn gold, while pomegranates offer vivid red fruit in addition to golden leaves. Liquidambar trees turn golden, flame-colored, or deep burgundy red depending on genetics, soil chemistry, and temperature variations. Ornamental pears range from orange to red, as do peach and apricot trees.

Liquidambar is a popular garden tree that offers not only reliable fall color but also star-shaped fruits that are a popular food source for several species of birds.
Pomegranates provide not only an abundance of fruit in the fall, but a blaze of autumn gold. We spotted this tree on old Topanga Canyon.
Autumn wildflowers include the brilliant red California fuchsia, a favorite with hummingbirds.
Sycamores and non-native but beautiful elms turn this corner of King Gillette Ranch into an autumn picture postcard.
The Liquidambar, a popular garden tree that is native to the Southeastern U.S., turns gold, scarlet, and even pink when the nights begin to get cool, bringing a taste of fall color to gardens throughout the area.
Cottonwood is one of the Santa Monica Mountains most reliable sources of autumn gold. This tree has been colonized by evergreen mistletoe. Garden elms aren’t native but they are a beautiful source of autumn color. This tree grows among the sycamores at King Gillette Ranch.
Ornamental pears are something of a nuisance for gardeners—the branches can be brittle, and the roots are invasive, but their scarlet leaves are beautiful in the fall and the small round fruits are much loved by birds and squirrels.
As bright as any of the autumn oak leaves that surround it, this nanday conure is an unlikely emblem of autumn, but just like the native birds, it is taking advantage of the fall bounty in the Santa Monica Mountains.

The bright red flowers of California fuchsia and the fluffy white seeds of coyote brush add a different note to fall in the chaparral, together with the red berries of the toyon, and the small pumpkin-like fruit of the coyote gourd—scattered like a handful of oranges by the side of the road.

Fall color in the local mountains is temperamental. Some years are too warm, or the Santa Ana winds strip the leaves before the show gets under way, but in a good year the color lingers into midwinter, and there is always some glint of autumn red and gold even in the driest, hottest year. Who says we don’t have seasons?