In recent years, the impact of surface heat islands in urban street canyons has become increasingly apparent. However, the research on the use of trees to mitigate surface heat islands remains limited. To address this gap, this study combines experiments and simulations to analyze the cooling effect of trees on surface temperatures under varying timeframes and layouts in an east–west street canyon. The results reveal that the temperature of the road decreases by 10–15 °C, which is 2–4 times greater than that on the south side. Moreover, at 5:00 p.m. in the afternoon, the cooling effect on the south side is 10.3 °C, which is twice that of the north side. In practical planning and design, the diameter of the tree canopy should be maximized, and trees with leaf-area densities greater than 1.5 m²/m³ should be selected. Additionally, the layout of trees should be optimized to maximize the tree canopy coverage. These findings have important implications for optimizing plant selection and placement in street canyons.

Numerous experiments have shown that trees can reduce the energy consumption of adjacent buildings, but little research has been carried out on how leaf area density (LAD) and the distance between walls and trees (D_W-T) in different orientations affect the energy consumption of rural houses. Using an investigation method, a simulation method, and a remote sensing information extraction method, the impact of different tree-planting scenarios on the energy consumption of typical rural houses was analyzed. The results show that the energy-saving effect becomes more prominent with a higher leaf area density of trees in summer. Under the same conditions, Osmanthus fragrans is the most effective tree, followed by Koelreuteria paniculata, and then pomegranate. Moreover, the energy-saving rate of the rural house increases with a decrease in the wall–crown distance of the tree. For instance, when a Koelreuteria paniculata is planted on the west side of the rural house with a wall–crown distance of 1–3 m, the energy-saving rate ranges from 4.38% to 9.81%. Additionally, the planting orientation of the tree affects the energy-saving rate, with the west-facing orientation being the best and the north-facing orientation being the worst under the same conditions, and the energy-saving rate of the best orientation (west-facing) ranging from 2.11% to 14.98%. By establishing a comprehensive model, it was found that planting Osmanthus fragrans on the west side of a rural house with a 1 m wall–crown distance yields the best energy-saving effect. The results of this study can provide theoretical support for planting trees around rural houses from the perspective of energy saving.