Glyphosate is a broad-spectrum systemic herbicide that can be used to control Phragmites. Since the herbicide needs to work into the underground rhizome and root system to be most effective, the key to using the products involves allowing the Phragmites stem to flower out. In Delaware this is generally mid- to late July, and once flowered out the plant can be treated at least up until the first frost. If glyphosate is sprayed prior to flowering, it will generally brown up the exposed stem, but since not much product translocates underground, the plant will resprout later in the growing season.
If Phragmites is growing in a dry or upland area, the popular herbicide Roundup can be used on it. This needs to be the agricultural formulation of the product that contains 41% glyphosate. Any generic formulations that have the same active ingredient makeup can also be used (RazorPro for example). For a ground application mix 2 ounces of herbicide per gallon of spray solution (put 2 ounces of herbicide in the sprayer then add water to the one gallon mark or multiply out based on size of tank). Then apply to the plant on a spray-to-wet basis, meaning get a nice coating over as much of the green stem as possible, but not so heavy as to run off the plant. Keep in mind that glyphosate is broad-spectrum and has the potential to injure any green plants it comes in contact with. Care must be taken with spray drift. Always read and follow all herbicide label recommendations also.
If Phragmites is growing in a wetland area, the aquatic formulations that contain 53.8% glyphosate must be used. Products available the last several years have the names Rodeo, Aqua Star, Aqua Neat, AquaPro, Glypro, Aquamaster and Eagre. Again mix 2 ounces of herbicide per gallon of spray. With these products a nonionic surfactant approved for used with herbicides must also be added at the rate of ¾ ounce per gallon of spray. The surfactants are available at local agricultural supply stores (The Division of Fish & Wildlife uses LI-700 available at UAP Northeast, 302-629-3047). Sources for aquatic glyphosate are:
CWC—800-380-9903
Timberland—804-520-0789
Arborchem—717-766-6661
Agriliance—800-762-3837
SePRO Corporation—860-651-5583
Outdoor mail order companies such as Ben Meadows and Forestry Suppliers also carry them.
Private contractors can also be hired for ground applications. Following is a list of companies that do work in Delaware:
Envirotech, Rehoboth Beach, DE, Todd Fritchman, 302-226-5474
Weed Pro, Salisbury, MD, Jim Samis, 410-742-2973
Restoration Ecological Services, Easton, MD, Dave Hardin, 410-820-7465
JCM Environmental, Georgetown, DE, Dave Saveikis, 302-854-9138
Prepared by William L. Jones, Fish & Wildlife Regional Manager, Private Lands Program, Delaware Division of Fish & Wildlife, 89 Kings Highway, Dover, DE 19901