Members of the local environmental group are delivering the notices to neighbors to warn against the use of chemicals on lawns, shrubs, and flower gardens, and to recommend nontoxic choices.

On a recent walking tour around one Newton Centre neighborhood, Lucia Dolan and Karen Albert, two of the three co-chairs for the Green Decade Coalition’s Committee for Alternatives to Pesticides, considered carefully which homes they should target.

Dolan said she looks for the tiny yellow flags stuck into lawns indicating they have been treated by a landscaping company using pesticides, and approaches only those front doors. Albert puts the door hangers everywhere.

“It’s like second-hand smoke,” she said. “In some ways smoking is seen as a personal choice, but everybody has to breathe the air.”

The grass-roots organizers in Newton may soon be joined by others statewide. Earlier this month, Maeve Ward, the third co-chairwoman of GreenCap, participated in a conference in Worcester aiming to start a Northeast regional anti-pesticide coalition.

The environmentalists have compiled lists of alternative treatments for lawns, shrubs, and flowers. They also recommend training courses for landscapers through the Northeast Organic Farming Association.