How to Kill Phragmites
- 1). Mow the phragmites down to or near ground level with a power weed cutter in summer once the plants are 5 to 6 feet high.
- 2). Remove the cut plant material, bag it and throw it away. Do not attempt to compost it. Many home compost piles do not reach high enough temperatures to kill any phragmites seed among the plant material.
- 3). Spray the phragmites once it regrows to 3 to 4 feet in height, before early fall at the end of the growing season. The Environmental Protection Agency (EPA) has approved glyphosate- and imazapyr-based herbicides for control. In wetland areas, the EPA recommends using Rodeo, which is formulated to break down quickly in the environment. Follow and do not exceed all manufacturer instructions for application methods and amounts. Spray while backing out of the stand to avoid getting herbicide on your clothes.
- 4). Re-spray any regrowth you spot for the rest of the growing season once it reaches 3 feet in height.
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