Don Barry, the owner of a lawn care company in Canada, believes a mixture of iron powder and water could be a useful alternative to herbicides, the Telegram reports. Barry has tested the mixture, which has been reviewed by the National Research Council, on his personal lots and put it to use for customers.

Barry’s company, Green Lawn, is located in St. John’s, Newfoundland, Canada. In 2012, the providence banned the residential use of a group of active ingredients that were common in herbicides. The alternatives on the market were not working, Barry says, so he took matters into his own hands and developed the iron-based mixture.

Although, Barry says, the mixture leaves the grass slightly blackened, the color is gone after mowing. The mixture applied to the surface and taken in by the plants. “They just have different tolerances,” he told the Telegram. “Dandelions have a lower tolerance to iron than grass does.”

Although Frank Smith, a chemist and member of the Coalition for Alternatives to Pesticides in Newfoundland and Labrador, said “certainly iron is harmless,” groups like his own are pushing for more regulations that could challenge ingredients in alternative pesticides, like Barry’s.

Read the full story at the Telegram.