“Hi, I’m a Terra Firma vegetable, and it’s been 120 days since my last drink.”
There aren’t many places in the United States where you can reliably grow fresh fruits and vegetables in the winter without irrigation. In most of the country, it’s simply too cold to grow vegetables at all. Most fresh produce eaten in the U.S. between November and April comes from the Desert Valleys of Southern California, Arizona, or Mexico. These are deserts where it hardly rains all year. Water comes from hundreds of miles and several states away, or from groundwater sources that are considered by most experts to be entirely unsustainable in the long term.
Don’t get me wrong — I’m not bashing irrigation. Here at Terra Firma, like at every other farm in California, we enthusiastically irrigate our crops for 6-8 months of the year, depending on the weather. And almost all of the crops we grow during the winter are planted during the dry months, which means they are irrigated for at least part of their lives.
But Terra Firma’s local region is fairly water-sustainable — at least compared to places like the Imperial Valley. For example, our area gets an average of 18 inches of rain every winter: more than enough to grow a crop of wheat, garlic, onions, broccoli, lettuce or other cool-season crop with little or no irrigation. Kern County, at the Southern end of the San Joaquin Valley, gets just 4 inches in comparison. And our summer irrigation water comes from a local reservoir just five miles away. It has never gone dry. In fact, our water district has never restricted deliveries to anyone, even during droughts.
It’s not as warm in our area as it is in the desert growing regions during the winter, which means that winter vegetables don’t grow as quickly as they do further south.  Still, most years, we avoid the type of extreme cold — roughly below 25 degrees — that will kill just about any vegetable.
But as I mentioned in last week’s newsletter, the rain that makes it possible for us to grow winter crops without irrigation also makes other things harder — particularly weed control and harvest.  That can make it more expensive for us to grow winter crops than for farmers in the deserts.
I think that farms growing crops locally for Bay Area markets have not done a good enough job of telling the story of how our crops are “Rain Fed”.  As farmers, we probably take it for granted.  But I think that many people shopping for winter vegetables probably don’t know that locally grown winter vegetables don’t just have a small carbon footprint than seemingly identical ones grown in the desert.   They also have a smaller water footprint.  And on the sustainability index, that’s a big deal.