Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. Experiments were conducted on 2- and 3-year-old ‘Autumn Spire’ red maple (Acer rubrum) liners. A traditional hydraulic sprayer with vertical booms between tree rows was used to apply the spray applications. Application rates were 10, 20, 30, and 40 gal/acre for the 2-year-old liners and were 20, 40, 60, and 80 gal/acre for the 3-year-old liners. Nylon screens were used to collect spray deposition of a fluorescent tracer dissolved in water, and water-sensitive papers were used to quantify spray coverage inside canopies. Spray deposition, coverage, and droplet density inside both 2- and 3-year-old liner canopies increased as the application rate increased. The minimum rates to spray 6.6-ft-tall, 2-year-old ‘Autumn Spire’ red maple liners and 8.7-ft-tall, 3-year-old liners were 20 and 40 gal/acre, respectively. An exponential equation was derived from these results to estimate the spray application rate required for different tree liner heights and to minimize excessive chemical use in rapidly growing tree liners.