Fall is upon us, the season so aptly described by the poet Mary Oliver as “the old gold song of the almost finished year.” Harvest is done, acorns are littering our driveways and trails, and deciduous trees are recoloring and casting off their leaves. Best of all, although the days can still be quite warm, there is that faint flirtatious promise of the long-awaited rain.
I’ve often heard it said that California “has no seasons.” Instead of four distinct phases divided by the equinoxes, we Californians must make due with only two — hot dry summers and cool wet winters. In this view, fall is simply the calm before the storm. A time when not much is happening out there in nature.
In truth, fall is anything but static, especially in the North Bay. Nature is super busy out there. The next time you take a hike, try making a list of the changes you notice. Here’s my short list:
The days are not only getting shorter, but the character of the light is different. It seems softer, less harsh, more golden.
Leaves are changing color but not all at the same time or rate. Some stay yellowish and orange, others become vibrantly red and purple. Still others are just plain old brown, or still green.
Birds are migrating. Recent arrivals include hermit thrushes, varied thrushes, and very vocal golden-crowned sparrows with their descending mournful “oh dear me” call.
It’s easy to spot deer trails in the dry grass, peppered with piles of oblong pellets. Bucks have rubbed the velvet off their antlers and are acting strange.
Spiders are everywhere. They’ve been here all along, but now the females are larger and webs are more visible on dewy mornings. On warm breezy days, I can catch a glimpse of tiny ballooning young spiders, hoisted on shiny strands of gossamer silk by the wind.
None of these observations are unusual. Yet, have you ever wondered why the light changes?
Questioning the light
How do plants sense that winter is coming? Why do leaves change color? How do birds know when to migrate, deer know when to mate, or spiders know when construct their silky egg sacs?
Answers to these questions, like many in nature, are not fully understood by humans. We do know, however, that the mechanisms that trigger seasonal change in the responses of plants and the behavior of animals involve physics, chemistry and biology.
Let’s start with the light. The earth is tilted 23.3 degrees from a vertical axis, always towards the North Star. The axis is an imaginary line running from one pole to the other. As it orbits, our planet presents a different aspect to the sun. In summer, the northern hemisphere is tilted toward the sun while in winter it is tilted away. Because we are also spinning on our axis one full turn every 24 hours, this tilting affects day length. The northern hemisphere receives much more total light during a 24-hour period in summer than it does in winter.
But why does the light look different? Imagine you’re holding a flashlight exactly perpendicular to a black piece of paper. The light hits the paper directly and forms an exact circle. Bright intense summer sunlight. Now tilt your flashlight so the light hits the paper at an angle. Here the light forms not a tight circle but a diffuse oval or egg shape, spreading the same amount of light over a greater swath of paper. This is sunlight in fall and winter.
Where to see great fall colors
You can’t really drive through Sonoma County without passing some of the most breathtaking fall colors in California, but here are a few destinations to put on your checklist:
Annadel State Park, Santa Rosa: To see the fall foliage from above, hike through Annadel State Park. Oak trees surround the walking paths leading to the hills. You’re rewarded for your efforts with breathtaking views of autumn sunsets.
Spring Lake, Santa Rosa: For those who prefer a leisurely autumn stroll - with family, friends or alone - follow the paths around Spring Lake and see the fall colors reflected in the water. Dress in layers and enjoy the park with less people - thanks to the cooler temperatures.
Highway to fall, various locations: As the seasons change, fans of fall and Instagram photographers join wine-lovers on Highways 12, 29 and 128, taking in the autumn scenery of Glen Ellen, Kenwood, Bennett Valley, Alexander Valley, Geyserville and Healdsburg from their car before making pitstops at tasting rooms and restaurants.
Red vine, various locations: In wine country, fall paints vineyards orange, yellow and red and some wineries have added specific foliage to highlight the season. At Chateau Montelana Winery in Calistoga and Jordan Winery in Healdsburg, to name a couple, red vines cover winery buildings.
Beringer Vineyards, St. Helena: An autumn drive through the historic elm tunnel on highway 29, en route to Beringer Vineyards in St. Helena, is like a fall rite of passage as the leaves turn yellow and gold.