MADISON – New England’s largest greenhouse grower of vine-ripened tomatoes plans to build a second greenhouse at its central Maine site, nearly doubling its year-round growing space.

Backyard Farms LLC is scheduled to begin construction this fall on the new 18-acre, state-of-the-art greenhouse with the first harvest expected a year later. Backyard Farms opened a 24-acre greenhouse last year.

“With this second greenhouse, we expect to bring our local work force to more than 175 employees, offer new tomato varieties and meet the increasing demand for our locally grown, top-quality tomatoes-on-the-vine,” Backyard President Roy Lubetkin said.

At a cost of more than $20 million, construction of the new facility will give the company nearly 2 million square feet of greenhouse growing space. About 75 workers will be hired for the new greenhouse next spring.

Backyard Farms has found success after taking up the challenge of stretching the agricultural calendar in a state well-known for cold weather and short growing seasons. Since its first harvest in January 2007, the Lexington, Mass.-based company has sold more than 20 million pounds of tomatoes to retailers that include a big regional supermarket chain.

It also claims to have created one job locally for every three jobs at Backyard Farms.