The change was driven by Kickstarter and social media feedback, he said. "Folks were like, 'Look, this is amazing, but none of this fits my space.'

"Three feet by 2 feet would fit on any fire escape in any city," Weiner added.

The company is teaming up with firms that make small raised gardening beds, the sort you could put on an apartment balcony, but it's also designing Urbmats for indoor use. The idea is to lay one on a table or even hang it on a wall. Weiner hopes to add LED lighting, too.

The products are inspired by the victory gardens of the world wars. Johnson talks about them in his class, and Weiner remembers hearing stories of his grandmother and great aunt's own victory gardens in Northwest Washington.

Weiner could see the appeal of many people growing their own fresh food. But the farm management class underscored for him how much effort it takes to start and manage even a small garden.

"The thought of doing it is just daunting for people," he said. "I thought if I could remove like 90 percent of that, I might have something."

Julie Lenzer Kirk, executive director of the Columbia-based Maryland Center for Entrepreneurship, which runs a business incubator and two accelerators, liked the idea immediately when Weiner pitched it to her in March. The company joined the center as an affiliate the same day.

When she's told early-stage investors about the mats, "they immediately want to go and buy one," Kirk said.

The mats are made of polypropylene — like shopping bags — in North Carolina. Staffers make the seed balls and assemble the package in Hunt Valley. Assembly time per mat: three minutes. By hand. Eventually that can be automated, but not for a tiny company just getting started.

"We'll be able to invest in machinery later once we're scaling," Weiner said. "We can probably do 3,000 units a month right now, just in our small little basement."

Kickstarter funds will allow the company to rent a 5,000-square-foot facility. Nearly 1,300 people backed the firm's Kickstarter campaign, which emphasized the company's healthy food mission and included donations of mats for schools.

"We had people give us $5,000 just because they believed in what we were doing," Weiner said.