Windbreaks are common sites around Iowa farms and acreages. A well planned windbreak will moderate hot and cold temperatures, reduce dust and snow, save money in home heating costs, and add monetary value to your property. Windbreaks should be located on the north and west sides of the area to be protected. They should not enclose all four sides or a "dead air pocket" will be created. Plant the windbreak at least 100 feet from the home and buildings but not more than 350 to 400 feet away. Distances less than 100 feet will prevent summer breezes and pile unwanted snow close to the house. Distances greater than 350 to 400 feet will reduce or nullify the positive effects. Extend the windbreak 50 to 100 feet beyond the buildings on the south and east ends. This will eliminate snowdrifts that form at the ends of the tree rows and protect the area as winds shift.
Ideally, a windbreak would contain eight rows of trees and shrubs:
Row 1: dense, low-growing shrubs on the windward (north and west) side
Row 2 tall shrub or low-growing tree
Rows 3-6: four tall tree rows including two fast-growing and two long-lived species (can be either four deciduous or two evergreen and two deciduous
Rows 7-8: two evergreen rows nearest the farmstead
This combination of trees and shrubs will provide year-round protection, maximum ground area protection, coverage from ground-level up, rapid growth, and long life. An eight row windbreak will require an area 110 feet wide for planting. If there is not enough room for eight rows, eliminate rows beginning with the tall tree rows. The smallest number of rows to provide an effective windbreak is three; two rows of conifers and one outside row of shrubs or small trees. A one row windbreak loses trees easily thus losing its beneficial to protect the area at ground level.
Plant rows of trees and shrubs in an alternated or staggered pattern, using adequate spacing. Within the rows of the windbreak, large conifer trees should be spaced 16 to 25 feet apart, and small conifers 10 to 15 feet apart. Deciduous trees should be planted 8 to 15 feet apart and shrubs should be planted 3 to 10 feet apart. The distance between all rows should be at least 16 feet. Wide spacing will allow for full development of trees and long windbreak life. Select trees for your windbreak based on your climatic conditions, soil type, drainage, soil pH, and topography of your land. Evergreen trees work well in the center of the windbreak because they provide year-round benefits. However, not all sites (heavy soil, poor drainage) are suited for evergreens. Deciduous trees can be used in these areas by increasing the number of rows from two to four to provide wind protection in the winter. Use as many species as possible to avoid large losses if your windbreak is attacked by disease or insect pests. The following species are often used in Iowa windbreaks.
|Norway Spruce||White Spruce||Black Hills Spruce||Colorado Spruce|
|Douglas Fir||Arborvitae||Red Cedar||Scotch Pine|
|White Pine||Red Pine||Concolor Fir|
|Cottonwood||Hybrid Poplars||Silver Maple||Hackberry|
|Green Ash||White Ash||Red Oak||White Oak|
|Nanking Cherry||Highbush Cranberry||Spirea||Hazelnut|
A well-planned and growing windbreak offers many benefits. For additional information, purchase PM543 Planning and Management of Farmstead Windbreak ($.50) at your local Extension office.
This article originally appeared in the May 3, 1996 issue, pp. 65-66.
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