The “cool” in “cool-season crops” means something different when it comes to California’s deserts in winter.
For example, winter highs average 69°F to 80°F from December through March in the Palm Desert of southeastern California. Lows average 45°F to 54°F during the same time. In the more arid southern tip of the San Joaquin Valley, winter highs usually average 60°F to 71°F and winter lows average 41°F to 46°F.
Garret Powell, general manager of sales at Peter Rabbit Farms, likens California’s deserts in winter to summers for most of the rest of the country’s farming regions.
“Sunny days and cool nights create an ideal growing region for wintertime,” he says.
Speaking specifically of the Coachella Valley, where Peter Rabbit has been a seasonal grower of bell peppers, leafy greens, and eggplant for 75 years now, Powell adds that there is little rain and ample available water in the form of reliable aquifers.
“It means that we’re able to grow all sorts of vegetables here,” he says.
Steve Adlesh, director of sales and marketing of Beachside Produce, describes California winter desert growing as an essential element for any company that wants to provide vegetables to customers year-round. Powell similarly describes the time and place as the natural transition point for growers and distributors that grow in Mexico and South America in early spring and elsewhere in the U.S. in summer.
For cool-season vegetable crops like broccoli, cauliflower, celery, Brussels sprouts, cilantro and kale, the unique winter climate of California’s deserts is beneficial, Adlesh adds.
“Those have to be in a climate where you’re not going to have much rain, and in the desert region, there’s really little to no rain during December, January and February,” he says.
Weather is Everything in the Desert
Despite being essential to a year-round vegetable strategy, winter growing in California’s deserts comes with potentially unexpected weather-related challenges.
“The thing we worry about in the desert are the freezes and freezing temperatures,” Adlesh explains. “It can get into the 20s when you get into late November to late December.”
While most cool-season crops can tolerate a freeze, it results in logistical difficulties.
“[A freeze] curtails the harvest because you have to let the produce, especially the lettuces, thaw out before you can harvest them, or you damage the tissue, and it’s just no good for the customer,” Adlesh says. “If you have ice in the morning and you can’t start harvesting until 11, obviously the production is going to decline and there’s going to be a lack of supply. So that can be a deal breaker if we have a really cold, cold winter.”
However, this winter looks like it will potentially be warmer than usual. In early October, the National Weather Service announced a weak La Niña condition, which usually means drier and warmer winters for Southern California, had been confirmed. At the end of October, it projected higher-than-average temperatures will likely exist for the area through the end of January.
This fits with what Peter Rabbit Farms has experienced in the Coachella Valley, according to Powell.
“This is a peculiar fall, we’ve had about 12 [degrees] to 15 degrees of higher-than-average temperatures for the last two weeks,” Powell reported during the first week of November. “This season has been getting much warmer temperatures than average. So, it’s really brought all the crops forward a little bit. I think this year we started our red peppers maybe 15 days earlier than normal.”
Desert Weather Giveth and It Taketh Away
What the weather does in the desert can have outsized impacts on winter vegetable markets.
For example, Powell explained that while Peter Rabbit Farms was able to start its fall bell peppers early and get good color on them earlier; so too were all the other fall and early-winter pepper growers in the desert.
“The guys in Central California were allowed to keep going, and it has created a pepper market where you have a lot of suppliers that are either ending their season and then you have a lot of suppliers who are now starting earlier and getting started,” Powell says. “So, there’s been high availability of peppers out there, and that’s the challenge.”
The inverse is also true.
“Right now, the markets are so high due to Mother Nature,” says Adlesh, speaking of the hail that hit some greens-growing regions. “It’s crazy. There’s lettuce, $40, $50; romaine, $40, $50; green leaf, $40, $50. That’s because of what Mother Nature threw at us here about a month ago.”
While the success of all agriculture rests on the whims of weather, Adlesh says that is especially true in the California deserts in winter given the extremes in play and what that weather can mean for markets.
“It’s hard to make money in the desert, period. We go down there to keep our customers in supply year-round, but it’s a huge risk for all the shippers that do year-round programs,” he explains. “You just plan what you need for your contract and, outside of that, don’t take any chances, because if the if the weather is nice all winter and the supplies are heavy, it can be an absolute nightmare.”
Different Sort of ‘Winter’ Desert Vegetable
While sweetpotatoes aren’t grown in California’s deserts in the winter, with harvest usually wrapping up at the end of October, they are in highest demand during winter holiday meals and are grown in California’s deserts. These deserts are uniquely well suited to sweetpotatoes’ growing needs, according to Jeremy Fookes, director of sales at AV Thomas Produce.
Fookes explains that the massive day-to-night temperature swings, sometimes as much as 40 degrees to 50 degrees, common in California’s deserts are essential to sweetpotatoes’ ability to develop the best flavor. The nature of the desert soil is also important, he adds, describing a small patch of California’s Central Valley between southern Stanislaus County down through northern Merced County as perfect “for producing good looking sweet potatoes.”
“The soft, sandy soil allows for the shape of the potatoes to develop the clean look to them that makes for high-quality, aesthetically pleasing potatoes,” he says. “There are certain regions throughout the country or even the world that produce good quality wines. Well, it’s the same thing with sweetpotatoes and a lot of other crops.”
