Planting a shelter belt reduces the impact of wind on an area, slows soil erosion on farmed and disturbed land and slows the evaporation of important moisture at the ground level. Green ash trees grow up to 65 feet tall with a canopy spread of around 30 feet wide. The tree sheds its leaves in the winter and grows in USDA plant hardiness zone 2 and higher. Each year, a green ash tree grows between 4 and 24 inches, depending on soil conditions, climate and nutrients.
Calculate the number of trees you will need. Measure the distance of the intended shelter belt. Space green ash saplings 8 feet apart. For a 500 foot span, you will need approximately 62 trees.
Ask your local nursery for an estimated price on the number of trees you need and compare it with a mail order source. If you are ordering a large number of trees, ask about bulk discounts at both sources.
Purchase the trees in the late winter and plan to have them arrive just as the ground is beginning to thaw. Plant the new trees as soon as the soil is soft enough to dig and work with.