The Agriculture Department, which approves crops for commercial planting, is a case in point. Its authority stems from its responsibility for protecting American crops from plant pests, which typically are insects or pathogens.

That responsibility extends to certain G.M.O. crops because for many of them, the foreign gene is inserted through the use of a bacterium, or the inserted DNA contains a genetic “on” switch from a plant virus.

But companies can get around that oversight by avoiding components from plant pests. In Scotts’s newer grasses, for instance, the foreign genetic material comes only from other plants and is inserted with a gene gun rather than by the bacterium.

“If you take genetic material from a plant and it’s not considered a pest, and you don’t use a transformation technology that would sort of violate the rules, there’s a bunch of stuff you can do that at least technically is unregulated,” Jim Hagedorn, Scotts chief executive, told analysts in December 2013. He said the company nearly shut its biotech program after the previous mishap, until it hit upon the new strategy and created “a stunning array of products that are not regulated.”

Image Peter Beetham, chief executive of Cibus, which uses genome editing to modify plants. Credit... Sandy Huffaker for The New York Times

The company recently started testing the grass on the lawns of its employees. But a spokesman said the grass was years from reaching the market.

A spokeswoman for the Agriculture Department said the agency was acting within the authority given to it by Congress and that even if it did not have oversight of a particular crop, the F.D.A. or E.P.A. might still be involved.