June 30, 2009
Most landowners and farmers are continually being plagued with problems associated with controlling unwanted trees and shrubs and keeping them from becoming established in fencerows, drainage-ditch banks, pastures, rights-of-way and other non-crop areas. According to Bob Frazee, University of Illinois Extension natural resources educator, what many people refer to as "brush," may actually be trees and shrubs known by the common names of box elder, locust, red cedar, mulberry, hedge, multiflora rose, soft maple, brambles, honeysuckle, sumac, hackberry, willow, trumpet creeper or even poison ivy.
The good news for landowners is that brush can be effectively controlled by mechanical or chemical methods or by a combination of these approaches. Frazee emphasizes that right now is an ideal time for attacking your brush problems and bringing them under control.
Mechanical brush control is usually very time-consuming and costly but may be necessary where herbicide use in not desirable. Mechanical control can be accomplished by cutting, girdling or grubbing the tree or shrub.
Chemical brush control is accomplished with the use of herbicides to control the plant or to minimize resprouting. Using herbicides is usually less labor intensive but does not remove the dead plants from the landscape. Frazee cautions that when using herbicides for brush control, it is very important to read and follow the directions carefully and completely as there may be restrictions associated with grazing periods and harvest clearances or application to aquatic areas, drainage ditches, etc.
There are several ways brush herbicides may be applied—foliar treatment to the leaves, a basal-bark or cut-surface treatment either onto or into the stem or trunk or application to the soil. According to Frazee, regardless of which method a landowner might select, it should be based on the specific herbicide being used, the site, the season of the year and the environment.
Brush herbicides are also categorized by their mode of activity. Some brush herbicides are selective, which means they will leave grasses unaffected while controlling brush and broadleaf plants. However, Frazee cautions that care must be exercised even with selective herbicides because these herbicides can injure desirable broadleaf plants if they are allowed to drift, run off or leach out of the treated area. Nonselective herbicides mean that the herbicide will control all vegetation in the area being treated.
The most recently published Illinois Agricultural Pest Management Handbook (2008) is available for $27 plus shipping by ordering directly from the University of Illinois' Publications Plus at their e-mail address (PublicationsPlus@uiuc.edu) or their toll-free number (1-800-345-6087). This publication contains the very latest University of Illinois recommendations for all types of agricultural weed, insect and disease problems—including brush control.
Chapter 8 of the Illinois Agricultural Pest Management Handbook is entitled "Brush Control in Illinois" and contains a great deal of practical information in easy-to-read tables. Table 1 provides a listing of the common and scientific names of 32 brush species typically found throughout Illinois. Table 2 lists the label clearances for the common brush herbicides. Table 3 lists all recommended brush herbicides, their generic name, trade name and rate of application. Tables 4 through 7 provide detailed information outlining all recommended herbicide treatments, their method of application and their susceptibility on 32 common brush species.
For individuals wanting to use the internet, Frazee reports that the Illinois Agricultural Pest Management Handbook (2008) is also available at www.ipm.uiuc.edu/pubs/iapmh. A pdf file of individual chapters and tables can be downloaded, at no charge, from this website and printed. If you do not have access to a computer, stop by your local University of Illinois Extension office and request their assistance in downloading and printing this 11-page document.