Studies were initiated to evaluate cultural methods of broadleaf weed control in turfgrass as alternatives to herbicides. Broadleaf weed exclusion by cool-season turfgrass species and cultivars under yearly nitrogen (N) regimes of no N, 0.5 kg N 100 m\sp−2, 0.5/0.5 kg N 100 m\sp−2, and 0.25/0.25/0.5 kg N 100 m\sp−2 were examined. Infestations were lowest in tall fescue and perennial ryegrass. Infestations differed only among cultivars of chewings fescue and Kentucky bluegrass. Infestations of tall fescue, perennial ryegrass and Kentucky bluegrass were lowest when 0.25/0.25/0.5 kg N 100 m\sp−2 yr\sp−1 was applied. Infestations of fine fescues were lowest when either 0.5/0.5 kg N 100 m\sp−2 yr\sp−1 or 0.25/0.25/0.5 kg N 100 m\sp−2 yr\sp−1 were applied. Exclusion of broadleaf weeds by mixtures of cool-season turfgrass species under yearly N regimes identical to the first study and including a 0.5/0.5/0.5 kg N 100 m\sp−2 regime were also examined. Infestations of turfgrass mixtures were intermediate to infestations of single species stands composing the mixture.