Global warming and urban heat islands result in increased cooling energy consumption in buildings. Previous literature shows that planting trees to shade a building can reduce its cooling load. This work proposes a model to determine the cost effectiveness and profitability of planting a shade tree by considering both its potential to reduce cooling energy and its purchase and maintenance cost. A comparison between six selected tree species is used for illustration. Using growth rates, crown sizes, and shading coefficients, cooling energy savings from the tree shades are computed using an industrial-standard building energy simulation program, offset by costs of purchase, planting, and maintenance of these trees. The result shows that most worthwhile tree to plant should have high shading coefficient and moderate crown size to maximize shading while keeping the maintenance costs manageable.