According to BostInno, Freight Farms, the Boston startup that builds automated farm systems in shipping containers, has closed a $7.3 million Series B round led by return investor Spark Capital.

News of Freight Farms raising a new round of financing came in April when it filed a Form D with the U.S. Securities and Exchange Commission. The Wall Street Journal reported that the round's other backers included other existing investors such as Launch Capital, along with a new investor, Stage 1 Ventures. Total funding is now $12 million.

Freight Farms makes automated, Internet-connected farms that are outfitted in large shipping containers. Called the Leafy Green Machine, these containers can produce 1,000 heads of lettuce a week. The company told the WSJ that more than 100 LGMs are now used in 30 states and nine countries.

Last fall, the startup introduced a smaller version of the LGM called the "LGC" that can produce 200 heads of lettuce a week.

Customers include food distributors, small farms, colleges and corporate campuses, including those for Compas Group, Sodexo and Google. In April, Freight Farms announced that it had partnered with Federal Realty Investment Trust to provide farm containers to 32 of the firm's shopping centers across several states.

"The mission of Freight Farms was always to make local food a global reality," Kyle Seaman, Freight Farm's director of farm technology, told me last year. "If you think about climate and other environmental conditions, urban agriculture is such a key pillar to making that real."

Freight Farms was founded in 2010 by Brad McNamara and Jon Friedman.