Important: Our final CSA box delivery for 2021 will be on Thursday, December 23rd. If you live in the Sacramento area, look for an email from Terra Firma advising about delivery changes for your location that week.

We have not seen the sun much here in the last month or so. Ever since the big October storm left the ground completely saturated with moisture, we’ve been in a pattern with little air movement and high pressure. Any time the sun comes out, it warms the ground enough that it gets foggy again as soon as the sun sets.

This is the infamous Tule Fog, scourge of Central Valley residents and drivers who have to pass through it. It sits close to the ground, dense and heavy, obscuring views and soaking everything with moisture. In years gone by, it was nearly-everpresent feature of winter in this area, but more recently it has disappeared almost completely.

Some folks claiming to be experts determined that the fog was caused by particulate pollution in the air, and gave credit for its disappearance to stronger air quality laws. That thesis appears to need revision, especially since the air here after the October storm was cleaner than it has been in the fall for several years.

Tule Fog may be hated by humans who like sunshine, but plants — at least the ones TFF grows in the winter — seem to love it. For one thing, it keeps the temperature almost the same day and night, a chilly 45-55 degrees. And it douses the plants daily with a spritz of heavy dew. Contrast this with the weather last November, for example, when it was sunny, dry and windy with temperatures rising and falling as much as 50 degrees daily.

Days in December are already short, but the fog makes them even shorter since the sun barely comes out. This has the effect of putting our crops into stasis, which is what allows us to take a vacation at the end of the year without worrying about missed harvests.

Fruit and nut tree crops also prefer the fog to sunny days and cold clear nights. The damp, constant chill that makes humans miserable puts the trees into a deep hibernation that better prepares them for another year of flowering and fruiting. The trees haven’t had a winter like this in many years, and it’s almost certain to result in bumper crops of all our summer fruit and nuts next year.

Of course, fog also helps the ground hold onto whatever rain we get. Up until Monday, we hadn’t received a drop of rain in over a month. But with no wind to blow the moisture away, and very heavy dew falling every night, we’ve been able to avoid irrigating almost completely. That is also a huge difference from the last couple of years, where we were watering crops sometimes even during rainstorms because the ground was so, so dry.

At Terra Firma, we’ve already gotten far more rain this fall than we had the entire winter last year. The 180 degree shift in the weather makes me very optimistic that we’ll get plenty more precipitation over the next 2-3 months. Any additional storms that do arrive will be welcomed by a damp, foggy airmass that will squeeze more moisture out of them and a moist soil that will help create runoff to fill creeks, rivers, reservoirs and the water table in general.

The drought is far from over, especially in areas south of Northern California. But it feels like we’ve broken the pattern that caused it. Fingers crossed.