A cook can’t always count on the contents of a community-supported agriculture box.

But CSA participants can count their annual pledges as insurance toward local farms’ production of high-quality foods, says chef Constance Jesser.

“The CSA boxes actually help our farmers plant,” says Jesser, referring to a decades-old model of farm management that allocates shares of the year’s harvest to supporters who pay months in advance.

A wide variety of produce, some unfamiliar, is a CSA shareholder’s reward. Using all of it, says Jesser, often requires cooks to “think outside the CSA box.” A Tuesday, Aug. 26, class at Jesser’s Jacksonville Mercantile will show students how.

“A lot of times, people get them and go, ‘Well, what do I do?’ ” says Jesser. “Most people are just so used to getting anything they want any time of year.”

Summer’s bounty, particularly zucchini, tomatoes and cucumbers, can overwhelm local farmers and home gardeners alike, says Jesser. Enjoying the harvest entails extending the same vegetable’s appeal over weeks, even months, of peak availability, she adds.

“You end up finding these big bags of zucchini on your porch in the morning,” she jokes of generous gardeners. “How do you make zucchini exciting?”

Instead of baking the quintessential bread, Jesser says she prefers zucchini in a vegan, curry-spiced soup that can be served hot or chilled. A vegetable peeler easily transforms zucchini into long strands for a pasta substitute that’s light on summer’s most sweltering days, she adds.

The iconic summer squash, along with tomatoes, is essential in the French staple ratatouille, which the chef freezes for use in fall and winter. Also on Jesser’s menu is a taste test of locally grown tomatoes versus grocery-store standards from elsewhere.

“There’s a big difference,” she says.

Differences abound among local CSAs. Most offer a few sizes and price points, usually several hundred dollars for several months of produce, supplied on a weekly basis. Many CSAs offer additional items — eggs, bread, meat, cheese, honey, dried beans and corn and other foods — that can round out a household’s grocery needs.

The CSA concept transfers some of agriculture’s inherent risk to consumers, whose produce portions may be short on a crop that failed or replete with one that exceeded expectations. The past several years have seen CSAs add wintertime programs, appealing when local farmers markets are closed. Fall is when farmers usually push to fill up their winter CSAs, but some will let new customers sign on for a few weeks.

“Our real bounty is in the fall,” says Anne Marie Ivan, co-owner of Wimer’s Swallow Springs Farm, which supplies Evans Valley CSA. “It’s a great way for people to give a CSA a try.”

Many CSAs require shareholders to pick up their boxes, but some farmers make home deliveries. Several of the region’s most prominent companies — Asante, Lithia Motors, Oregon Shakespeare Festival and Providence Medford Medical Center — have recently helped employees to participate in CSAs that deliver to the workplace. Southern Oregon University has a CSA available to students and staff.

“Some businesses are actually choosing to subsidize it as a wellness benefit,” says Wendy Siporen, executive director of Thrive, a nonprofit business-development organization that advocates for local food producers. “They also talk about building community with employees, too. … People get to know each other and share recipes.”

Recipes and farm news are staples of CSA newsletters that usually accompany shares. Short cooking videos are a new project for Siskiyou Sustainable Cooperative, one of the valley’s oldest CSAs, says Siporen. See episodes of “Lizzie’s Farm Kitchen” on YouTube.

Following are some recipes for zucchini pasta and vegan cucumber soup.

Reach freelance writer Sarah Lemon at thewholedish@gmail.com.