Research conducted from 2003 to 2005 at Michigan State University showed that leaves collected from a variety of species, particularly sugar maple species (Acer saccharum M.), mulched into established turfgrass resulted in increased spring green-up and fewer common dandelions (Taraxacum officinale W.) than control plots. The cool-season turfgrass plots in this research were managed at a low maintenance level (no irrigation, low fertilization and regular mower scalping) to promote weed establishment, resulting in extremely high dandelion populations. An experiment was initiated October 2004 to develop a better understanding of how mulched leaves would effect dandelion populations in properly maintained cool-season turfgrass. The objective of this research was to quantify the effectiveness of maple leaf mulch as an organic broadleaf weed control method at various fertilization rates and mowing heights. The experimental design was a completely randomized design in a 2x2x2 factorial, leaf species, fertilization, and mowing height. Leaf species were red maple (A. rubrum L.), and sugar maple (high sugar content) (A. saccharum M.) applied at 1.5 kg m^-2. Fertilization included 46-0-0 applied at 137.4 kg ha^-1 N annually and a control. Mowing heights height were 3.8 cm and 7.6 cm. Data collected in 2005 on a cool-season turfgrass mixture (Poa pratensis L. and Lolium perenne L.) included visual quality ratings, percent smooth crabgrass (Digitaria ischaemum Schreb. ex Muhl.) cover ratings, and dandelion population counts. Results obtained in 2005 indicate that, while fertilization had no effect on dandelion populations, mulched tree leaves, regardless of species, reduced counts by up to 84 and 72 %, provided by the sugar maple and red maple leaves, respectively.