The severity of your response to these invaders should depend on the numbers: When half the lawn is covered with weeds, it's time to get a soil test and renovate the entire lawn. For a scattering of weeds, a hand weeder or targeted spray is kinder to the lawn ecosystem. The stand-up sprayer at left ($25; weedblasterpro.com
) holds 16 ounces of any weed treatment. Pushing down on the handle dispenses a 3 1/2-inch-diameter mist beneath the 7-inch cone.