Three Palm Beach County farms got a guarantee on Tuesday they can continue to supply the nation with winter vegetables.

The county commission agreed to extend their leases for 35 years in the Agricultural Reserve, a 22,000-acre conservation area west of Boynton Beach and Delray Beach.

The reserve was designed as a sanctuary for farming and a rural lifestyle, but thousands of homes have been built there as growth has boomed in South Florida.

The county leases about 2,400 acres in the reserve to farmers, who grow peppers, cucumbers, squash, lettuce, eggplant and herbs for national distribution. Two farm owners asked the commission on Tuesday to continue their rental agreements through 2053 so they can confirm to grocery stores they will remain in business and guarantee their families a future in farming.

“The buyers for the big retail chains want to know we’ll be here,” Dick Bowman, a farmer west of Delray Beach whose family has grown peppers and cucumbers in the area for decades, said after the meeting. “There are global concerns about surviving and changing with the times.”

The county bought Bowman’s 938-acre property in 2001 for $38,461,000 as part of the conservation plan voters approved in 1999. It leases it back to him for $500 an acre. The other properties that won extensions on Tuesday were 195-acre T&D Cattle Company and Exotics, also operated by the Bowmans, and 262-acre Bedner Farm, which the county bought in 2001 and leases back to the family.

Palm Beach County voters signed onto to the Ag Reserve conservation effort in 1999 when they overwhelmingly approved spending $100 million to purchase 2,400 acres in the farming region for preservation. The county also created tougher building rules for developers, limiting the density of new construction and requiring preservation land to be set aside for each acre developed.

Over the years, commissioners have loosened development rules, making it easier for small agricultural land owners to sell their land for commercial development.

Meanwhile, suburbia has marched into an area where farming dominated. More than 7,000 homes have been built in the reserve, along with schools and a hospital.

County Commissioner Paulette Burdick questioned whether the county is getting a fair deal at $500 an acre, reduced from an initial $550. She urged county officials to find out “the true market value.”

But her fellow commissioners agreed to the extension without a rate examination. They said they want to encourage agriculture on the set-aside acreage.

“I would support making these 50-year leases, or 100-year leases,” County Mayor Melissa McKinlay said.