Digging, mowing, burning, flooding, grazing and treatment with herbicides are all methods used to control phragmites. A combination of applying herbicides and using one or more of the other methods generally produces best results. Treatment plans must be long-term, with re-treatment applied periodically. Early detection and application of control efforts are most effective for eradication of phragmites.
Digging by itself is generally not enough to control phragmites because of the plant's deep, extensive root system. Mowing is only effective when the stand approaches the end of the growing season. Early mowing actually encourages a thicker stand of phragmites. Flooding and burning are often not feasible.
Glyphosate and imazapyr are broad-spectrum aquatic herbicides used in conjunction with the methods described above to control phragmites. Surfactants must be added to herbicides to adhere to the plant leaves, stalks and rhizomes. Unless the herbicide specifically states that surfactants are included, they must be purchased separately and added to the tank mixture. The herbicides must be applied during the plant's growing season while the flowers are blooming.
Phragmites is a large, coarse perennial grass found in wetlands. It has little value for wildlife and reduces the area's biodiversity. Phragmites spreads quickly by long surface runners, making it difficult to control.