A string trimmer attachment apparatus and method for easy attachment to a lawn mower deck, without requiring the use of tools for attachment, by having an adjustable trimmer mounting platform which securely attaches to the lawn mower. A string-type powered trimmer motor on the bottom side of the adjustable trimmer mounting platform cuts the grass. An operating control located on the lawn mower controls the string-type powered trimmer motor. A pair of L brackets allow the adjustable trimmer mounting platform to firmly attach to the lawn mower without the need for a separate trimmer/edger appliance. No tools or lawn mower modifications are required to attach the adjustable trimmer mounting platform to the mower deck.