Many new windbreaks, wildlife habitat plantings, woodlots and other conservation tree and shrub plantings are planted each spring by enthusiastic tree planters.
After planting, treat your trees as you would any other crop, says Constance Miller, USDA Natural Resources Conservation Service state forester. Help them in their fight for survival against drought, weeds, disease and pests by giving them adequate care and protection. Visit your tree planting often throughout the year to determine if any attention is needed.
"An important step in establishing seedling trees and shrubs is removal of weed competition," says Miller. "The first year is extremely critical. Young trees depend on surface moisture to survive. Competition for moisture, light and nutrients by aggressive weeds and grasses can severely stunt or kill newly planted trees and shrubs."
Cultivation, herbicides and mulches are all effective in controlling weeds during the growing season when applied in the proper amounts and at the right times. The best time to control weeds and grasses is just before or during their seedling stage. Newly germinated weed seed can be killed easily by cultivation or chemicals. Established weeds and grasses can hide small tree and shrub seedlings, making weed control much more difficult.
Removal of competing vegetation about two feet on each side of the tree row, or in a four-foot diameter circle around each seedling, is most critical. Cultivation is the surest method to control weeds and retain moisture for the seedlings. Cultivation should not be too deep and should never ridge soil against the plants. Where moisture is sufficient and a vegetative cover between rows is desirable to prevent soil erosion, mowing vegetation between tree rows is recommended.
Natural or fabric mulches do a good job of weed control and moisture conservation, but initial cost is often higher than cultivation or herbicide treatment. "Fabric mulch has proven effective in reducing competition for moisture, but fabric can girdle, or cut into growing tree trunks if left unattended for several years. Landowners must be prepared to enlarge fabric openings to accommodate tree growth and prevent girdling, usually within 3-5 years of successful planting," says Miller.
Planting of aggressive grasses, such as downy bromegrass or tall fescue between plant rows, is not recommended. Those grasses will smother annual weeds, but will also give young trees and shrubs competition for moisture and nutrients. If perennial grasses are planted, consider using less competitive cool-season grasses sucvh as blue grass or rye grass, or short warm-season grasses like blue grama or side-oats grama.
New tree and shrub plantings should receive adequate weed control for at least three years until the roots have become well established, Miller recommends. The time spent protecting and maintaining conservation tree and shrub plantings will pay substantial returns in comfort, protection, and beauty.