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.
Plants can be purchased from a number of local and mail-order nurseries including the Iowa DNR State Forest Nursery. Often, bare-root is the most economical way to buy the large quantity of trees and shrubs needed to establish a windbreak.
The following species are often used in Iowa windbreaks. Other trees and shrubs can be used besides those listed here, but these species have proven to perform well when planted in appropriate soil conditions.
- Norway Spruce
- White Spruce*
- Colorado Spruce*+
- Douglas Fir*
- Red Cedar**
- Scotch Pine+
- White Pine**
- Red Pine*
- Ponderosa Pine*
- Jack Pine*
- Concolor Fir*
- Hybrid Poplar+
- Hybrid Willow+
- Silver Maple**
- Freeman Maple
- Hybrid Elm
- Red Oak**
- White Oak**
- Swamp White Oak**
- Black Oak**
- Bur Oak**
- Black Walnut**
- Shagbark Hickory**
- American Linden**
- Redosier Dogwood**
- Gray Dogwood**
- Silky Dogwood**
- Wild Plum**
- Nanking Cherry
- Black Chokeberry**
- Highbush Cranberry Viburnum**
- Arrowwood Viburnum**
- Prairie Crabapple**+
- Sandbar Willow**
* Native to North America
** Native to Iowa
+ Use these species sparingly. These species have traditionally been used in windbreaks but disease and/or insect issues have made them less desirable.
- Windbreaks from Iowa State Forestry Extension
- Windbreaks for Wildlife (publication)
- Tree Planting Basics
- Planting Bare Root Plants
- Community Tree Planting and Care Guide (publication)
- Care of Newly-Planted Trees
- How to Care for Newly Planted Trees through Winter
- Iowa DNR State Forest Nursery
- Successful Tree Planting from the Iowa DNR (pdf)
- Grass and Weed Control for Seedling Trees from the Iowa DNR (pdf)
Updated from an article that originally appeared in the May 3, 1996 issue of Horticulture and Home Pest News, pp. 65-66.