MADISON – A company that grows tomatoes in a huge greenhouse in Madison is planning to expand with a second greenhouse next year.

Backyard Farms says it will build a 17-acre greenhouse next to its existing 23-acre glass-covered greenhouse. When the new greenhouse opens, the work force will grow from 90 to 150.

Backyard Farms shipped its first vine-ripened tomatoes last January from the greenhouse, located on a former dairy farm.

The company says its Madison greenhouse is the largest in New England and among the biggest nationwide.