Use slow-release fertilizers for most ornamental plants, including lawns, especially in areas with sandy soil. These fertilizers are less likely to allow nitrates to wash through the soil into the groundwater. Sweep spilled fertilizer off pavement before it is washed away by rain or irrigation. Nitrogen and phosphorus from fertilizers have' been associated with many environmental problems, including excessive algae growth, depletion of the water's oxygen supply, and suffocation of aquatic life. Because soil sediment makes up most of the pollutant carried by runoff and most of the phosphates and pesticides entering Virginia's waters are attached to this sediment, controlling erosion will help control water pollution.
Landscaping can help control erosion by holding soil in place and reducing runoff.
Plant a vigorous ground cover on steep slopes to reduce erosion and runoff. Turfgrass is often impractical here because mowing is difficult and dangerous on steep terrain. Build terraces or a retaining wall on slopes. These can intercept runoff, giving water time to soak into the ground, and can make attractive planting beds. Be aware that altering the soil level near established trees can seriously damage their root systems.