Important Note: This will be the final week that you get your CSA box packed in the larger size boxes we use during the summer. Beginning next week, your box will be smaller. Make sure to check the label so you are taking the right size.
One of the hottest trends in locally grown food in Northern California is “dry farming”, the practice of growing crops without irrigation. The term was first applied to wine grapes, and the result was smaller crops of more intensely flavored fruit. In recent years, it has become popular to farm tomatoes this way and sometimes potatoes.
Almost all of the dry-farmed tomatoes in Northern California come from areas within 10 miles of the coast — places where the temperature rarely gets above 75 degrees and foggy nights and mornings are the rule. In that particular climate, a tomato plant can survive on soil moisture and condensation from fog which can end up amounting to several inches of water over the season.
Tomatoes grown this way yield much lower than those grown with irrigation — and the yields are directly related to how much it rains in the spring before and after they are planted. By all accounts, this year has been a tough one for tomato dry-farmers.
There is no third-party certifier for farmers who grow dry-farmed tomatoes, and I personally am pretty skeptical about the whole thing. Would these growers really watch their tomato plants die rather than irrigating them once or twice to keep them alive if it came to that? Would they drop the “dry-farmed” label if they did? their customers be able to tell the difference?
We can’t dry-farm tomatoes out here in the Sacramento Valley very often, although there have been a few years when we haven’t irrigated our first planting at all before harvest due to wet spring weather. (Interestingly though+, in cool, wet springs like those, our “dry-farmed” tomtoes have considerably less flavor than they do in hot years when we irrigate them.)
We do, however, carefully manage our tomato irrigation. We actually water the plants quite heavily prior to ripening the fruit, and then cut it off almost completely. We have found this not only makes the tomatoes taste better, but helps keep them firm and prevents splitting.
No, summer is not the season for dry-farming at Terra Firma. However, until very recently, you could make the claim that we were “dry-farming” most of our winter crops. Most years that we’ve been farming, natural seasonal rainfall has provided most or all of the water we’ve needed for our carrots, broccoli, leeks, spinach, etc. from late October through March. And there have been plenty of years when we have wished we could make it stop.
Last winter, however, we had to irrigate all winter long. Growing winter vegetables with irrigation instead of rainfall makes the whole process more predictable and controllable. You can plant, cultivate and harvest when you want, how much you want. But it’s kind of a drag. It has no soul. And the plants, unlike summer vegetables, are happier when it’s raining.
So for the record, we like dry-farming our winter crops. It’s raining hard enough today that we turned off our pumps, and we hope that this is a trend for the upcoming winter.
Just don’t ask why we don’t dry our tomatoes.