By: Kris Maher

A crackdown by Pennsylvania regulators on a seed exchange at a small library has put gardeners and advocates of locally grown organic food on alert across the country.

In June, the Pennsylvania Department of Agriculture told a public library in Mechanicsburg, Pa., that it couldn't distribute homegrown seeds. The agency said a planned seed-exchange program would run afoul of a 2004 state law requiring anyone who distributes seeds to conduct certain quality tests, adhere to labeling and storage rules and acquire a license.

The move is believed to be the first time a state has intervened in the growing seed-sharing movement, albeit one dwarfed by what the International Seed Federation says is a $12 billion U.S. industry.

There are an estimated 300 so-called seed libraries in towns and cities across the U.S., including Boston, Cleveland, Nashville and Tucson, up from about a dozen in 2010. Most are affiliated with public libraries, where residents can "borrow" seeds to plant in private gardens, then return others they harvest.

The rise of community seed libraries, which experts say is a throwback to a preindustrial era tradition, reflects increasing interest in locally grown food and urban gardening, as well as concerns over genetically modified crops. Advocates say the programs also nurture locally diverse, hardier seeds that can better withstand a shifting climate.

But the movement has attracted the attention of state regulators, who are taking a hard look at whether such libraries could spread invasive or even poisonous plants, and if they are distributing seeds that will reliably grow. On Monday, officials in Maryland, which like other states has seed laws similar to Pennsylvania's, adopted the latter state's approach and now also began barring libraries from distributing homegrown seeds.

Steve Malone, president of the Association of American Seed Control Officials, a membership group for state regulators, said seed libraries aren't automatically illegal.

"We're concerned about this sort of thing, but if people really want to do it, we want to try to figure out a way to help them do it right." He said most state regulators only recently have become aware of seed libraries, and he wasn't aware of problems associated with any seed library programs.

In Pennsylvania, Jonelle Darr, executive director of the Cumberland County Library System, said the state's requirements would be too financially burdensome for the Mechanicsburg library, which she says operates on a tight budget.

Instead of maintaining a collection of harvested seeds from residents, the library will use an old wooden card catalog to hold seed packets for tomatoes, lettuce and other vegetables and herbs donated by companies. The library still can host seed swaps among residents.

"The seed library community seems to think that a terrible precedent has been set," said Ms. Darr. "From my perspective, we really don't have much choice."

Matthew Dillon, director of Seed Matters, an initiative of the Clif Bar Family Foundation that seeks to conserve crop genetic diversity, said he worries that more cash-strapped libraries will shut seed initiatives. He said he thought Pennsylvania officials had overreached, and that the risks of seed exchanges were minimal.

Jay Howes, Pennsylvania's deputy secretary for agriculture and consumer protection, said state officials objected to the library accepting unsorted, undocumented seeds and then redistributing them to library patrons.

"What they proposed to do at the library fell under the definition of seed distribution, and if you're a seed distributor, you fall under the provisions of the act," he said.

Pennsylvania law requires seed sellers or distributors to conduct germination tests on seed varieties, which typically requires testing about 400 seeds for each lot at a cost of about $25 per lot. Even if libraries had enough seeds to test, the costs likely would be untenable.

Some advocates are pushing to exempt libraries from state seed laws. The laws primarily were intended to regulate commercial ventures, protect farmers and prevent the spread of dangerous plants on a huge scale, said Neil Thapar, a staff attorney with the Sustainable Economies Law Center in Oakland, Calif.

"We think some of these laws are being applied broadly, and some of these laws need to be changed," Mr. Thapar said.