Phragmite control

Asked July 18, 2018, 8:30 AM EDT

Can you tell me what is the best way to control the ohragmites that are taking over my property by a pond. Pretty soon they will take over my lawn.

Macomb County Michigan weed issues

1 Response

Phragmites (Phragmites australis) is a perennial grass that grows in low-lying, wetland or coastal areas. Phragmites is native to Michigan. However, there is also a non-native variety that is invasive to Michigan and can have negative impacts on wetland and coastal plants, animals, and aesthetics. Phragmites plants can grow up to 15 feet tall with leaves 2-2.5” wide and up to 15” long. Plants begin to flower with purple-brown feathery plumes in late July. Plants can spread by both seed and their extensive root and rhizome system. For more specific information on distinguishing among the varieties consult “A Guide to the Control and Management of Invasive Phragmites”.

The Michigan Department of Environmental Quality (DEQ) recommends a two-step approach to controlling phragmites infestations. The first-step involves treating the plants with a herbicide. The choice of herbicide used and the method of application will depend on the proximity to water, density of infestation, and the plans for the site following phragmites removal. Herbicides with the lone active ingredient of glyphosate or imazapyr have been shown to effectively control phragmites; herbicides that combine those two active ingredients can also be effective. These can injure or kill other plants, including your lawn and trees.

A permit is required if there is visible water located near the site at the time of application or it is along the shoreline of the Great Lakes or Lake St. Claire; contact the MI DEQ Aquatic Nuisance Control Program Staff at (517) 284-5593 for more information. Also, a list of approved aquatic herbicides needs to be consulted on the MI DEQ website (or see link below). With any herbicide application, it is important to read and follow all labeled information. Please note that depending on the degree of infestation repeated chemical application may be necessary.

These herbicides can be applied with a backpack sprayer, stem injection, or hand swiping for smaller, isolated plant stands. For larger stands. For moderate to dense stands, a boom sprayer or aerial application may be warranted.

The second-step is the mechanical removal of the treated aboveground plant material through mowing or cutting at ≥4”. Cut material should be bagged, sealed, and sent to the landfill, particularly if seeds are present. Composting is not recommended. If plants are mowed using a flail mower removal of plant material is not necessary. Clean all equipment following mechanical removal to avoid spreading seeds or rhizomes to other areas.

For more information on phragmites control, please visit the following web sites:

A Guide to the Management of Invasive Phragmites- Michigan Department of Environmental Quality

https://www.michigan.gov/documents/deq/deq-ogl-ais-guide-PhragBook-Email_212418_7.pdf \

A Landowner’s Guide to Phragmites Control- Michigan Department of Environmental Quality

https://www.michigan.gov/documents/deq/deq-ogl-Guide-Phragmites_204659_7.pdf

Aquatic Pesticides and Related Products Currently Approved for Use in Waters of the State- Michigan Department of Environmental Quality Water Resources Division

https://www.michigan.gov/documents/deq/wrd-anc-approvedherbicides_445623_7.pdf