by Bryon Walters
Phragmites australis, Common or Giant Reed, can be a very problematic invasive in wetlands and wet prairies. If left unchecked, it can form large monoculture, impenetrable jungles 6-10’ high. Usually nothing else will grow under the dense canopy. Large infestations can be controlled with high pressure, high volume, non selective herbicides, leaving the area brown and dead.
Small infestations should be dealt with as soon as possible. Here is a seep area that has about 24 stems.
September is a great time to deal with the stalks. You want to treat it before the large seed heads turn brown, ripening to the point of seed falling off. Early in the Fall, the seed heads may be young, green and unripe.
The only effective herbicides for treating Phrag are Glyphosate and Imazapyr. Both are non selective and will kill everything it drips on.
The high or good quality areas, the best approach to rid the Phrag and save the surrounding vegetation is a surgical approach.
First, starting in the back of a patch of Phrag, use hand pruners to cut the stalk off about knee or waist high. The lower the better, but personal comfort may dictate the height. Cast the long stalk you just cut with the seed head, off to the side laying it somewhat flat. If you just drop it where you cut it, it will remain upright and you will be confused and grab that stalk again thinking it needs to be cut. Use sharp pruners, I use Felco #2’s, to make a clean cut. You need to see the hollow hole in the remaining, standing stalk you just cut. If it is smashed closed, cut again just below your first cut. It should look like this.
Next, have a hand held bottle sprayer that is filled with 100% Glyphosate and a little blue dye. Slowly spray a straight stream into the hollow stem. It will hold various amounts of herbicide. You may want to practice spraying water into a straw before hand. The Phrag hole will be half the size of a straw hole. It takes a little practice and patience. When I cut the stalk I leave a small portion of a leaf sheath to use as a backboard when spraying into the hollow stem. It can stop the occasional overspray from running a stream of Glyphosate onto the ground or other vegetation. Sometimes Reed Canary Grass is all around and you don’t mind herbicide dripping on that. After getting in a rhythm, I may cut 3-5 stems in a group and then spray them. Don’t do more than that at one time because you may not find the stems. Get good with one’s and two’s before moving to larger groups.
Work moving backwards away from the stalk(s) you just treated. You do not want to step on, bending or breaking the stem you just treated. I can treat about 100 stems in an hour. I rarely cut more than that but on occasion I’ve had to.
An advisable follow up option would be to gather up the cut stems that are laying everywhere and put them on a pile. Working from the pile, I cut off all the seed heads and put them in a sack to carry off site. Even young green unripe seed heads could potentially ripen and reseed the area. It doesn’t take too long to do this. You’re reassurances are worth the little extra efforts.
I have successfully eradicated and eliminated Phragmites entirely from areas using this surgical approach. I’ve treated it with wonderful plants like Bog Goldenrod, Grass-of-Parnassus and Gentians growing right underneath the Phragmites. My follow up visits have shown zero damage to the native plants. Give it a try and you’ll be a doctor in no time.
grassland restoration network 
Thanks for yoir article. I know a few persons who use Plateau to control common reed. Have you tried it at all.
Have you found any of the native common reed in your area?
Thank you for your interest. I’ve never tried any other products because I get 100% positive results with Glyphosate. We don’t think the native species even exists here in Illinois. I don’t know anyone whom has ever seen it. Likely existent or hybridized with exotic.
I think the native species may still be in the the northern Midwest. The taxonomists in KS haven’t reviewed the current and historic specimens to determine its historic and current extent in KS where I live.
I have heard a report of native Phragmites being at Illinois Beach State Park. I have never seen it in Illinois myself. What is shown in your picture is the non-native invasive variety. In the native variety the stem is smooth and reddish above the nodes.
I bet the native subspecies does exist in NE Illionis. It is present and not rare in Walworth and Kenosha counties in WI.
We had a lot of success using this method also on regrowth areas following larger scale removals.
Thank you for your well -written and timely article. Phragmites has just appeared on roadside adjacent to roadside prairie maintained by the Jubilee Prairie Dawgs, obviously spread by County roadside mowing. The patches were small, so we applied dyed glyphosate (Roundup) to each leafy stem, wiping each stem using the saturated nappy glove-over-chemical glove (plus gauntlet) method. I prefer your method and will use it in future. I mention the glove-on-glove method to deter others from trying it on Phrag. One problem was that It was hard to keep the treated Phrag. out of your face. Another problem was accidental contact by others collecting seed around it.
If I were a land manager with a high-quality natural area, I would only offer a contract to someone who has proven they could do this type of quality work. I would pay a premium to have it done.
I am glad Byron has developed and proven this technique. In quality woodlands/savanna phragmites popped up in locations where we had burned brush piles. I tried cutting them with loppers and one of the site stewards painted 41 % glyphosate on the cut. However, the next year the phragmites was back just with less vigor. I later realized I made a rookie mistake of cutting the stems too high. These clones were later broadcast sprayed by contractors. I have not worked on this species since that time because I was occupied with other things.
I tried to get my park district to hand wick phragmites in a wetland reconstruction. When I visited after the phragmites was treated, I saw that spraying had been done and anything under or next to the phragmites had been annihilated. I came to terms with the fact that the rice cut grass and other things that had been seeded into the site a few years previously would grow back. The important thing was the spread of the phragmites clone had been stopped. However, in areas like Byron describes, where the vegetation won’t grow back within a few years, it is necessary to have the techniques in the toolbox he has shared with us. His technique is also much better than hand wicking because of both preventing damage to nearby plants and being less likely to get herbicide on the applicator. Good job Byron.
Good info thx 😊
Suzanne Coleman
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awesome information. that makes total sense! I have not had the need to treat phragmites yet, but in the event that I do I would try this approach for sure. love it!
With a wash bottle–Link to search https://www.google.com/search?client=firefox-b-1-d&q=wash+bottle+chemistry — you could stick the spout right in the stem or right on the edge. I have a feeling my aim would not be true.
I tried this with wash bottles at a workday recently. The fact that they must be burped constantly (air goes in where the liquid comes out) was a complicating factor. Spray bottles worked at least as well and were also good for treating isolated hybrid cattail as we went along.
I use the large horse syringes that you can buy at a farm supply store. Holds a lot of herbicide. No drips.
I find it interesting that it is suggested that one use 100% glyphosate when I have had complete kill at 50%
I do the same with Parsnip, which also has a hollow stem. But it only requires 10% Glyphosate
You say 100% glyphosate, but do you mean one of the undiluted aquatic-rated products, most of which are actually 52-54% active ingredient glyphosate (e.g. Rodeo, AquaNeat, Refuge, etc.)?
Yes, 209% concentrate from the jug, irregardless of the percentage of ai.
Syringes are available on eBay. Inexpensive.
What percent did you mean? You have 209
Thanks. I think I’ve got it 209 is is an easy typo from 100.
Using the same technique, I used a 15% concentration of glyphosate with 41% as AI on cut cattails, adding a vertical slit ( I use a knife to cut the cattails ) down about 6″ in the “stump” for greater surface area for absorption. I get a 100% kill rate with only minor follow-up from not visible shoots. I would also highly recommend the wash bottle for a much greater level of precision in applying. I’m not sure what was meant by the wash bottle needing “burping”; squeeze and release, it doesn’t get any easier than that.