As described in Plants of the Chicago Region, “Phalaris arundinacea, reed canary grass, is introduced from Eurasia. This grass is planted by farmers for pasture and erosion control. It is very common in marshes and other moist ground, often forming nearly pure stands…”
Below are two photo of recent treatment of RCG at Nachusa Grasslands.
A riffle with RCG treated with glyphosate and imazapyr a few weeks back. This herbicide mix is approved over water.Glyphosate & imazpyr on RCG along Wade Creek. Sedges and forbs dominate this section of stream which also has marsh marigold, skunk cabbage, riddel’s goldenrod, and grass of parnassus.
The bright green plant is not a grass but a sedge. The yellowing reed canary grass is hurt by the clethodim herbicide, but not sedges, rushes, forbs, shrubs, trees. But…most of us conclude some of the grass roots will still be alive and slowly emerge next year. Of late we are adding ammonium sulfate and a non ionic surfactant to the clethodim mix. If we knock back the invasive grass can the sedge meadow hold its own?Clethodim sprayed on RCG. At first glance you see just yellowing reed canary grass, but look for the tall thin bright green sedges that are unaffected. I saw those sedges and felt confident that a quick spray of this entire RCG patch would next year show sedges and forbs starting to dominate the ground. This is the attraction of a grass herbicide. From 2020, RCG yellowing while sedges are bright green with some sedges seeding. A missed RCG is bolting in the back ground. We use backpacks too, but this 50 gallon sprayer on the back of the 30 hp tractor is quite nimble for getting access to modest size patches for spraying RCG. The hand nozzle on the sprayer is used much more often than the boom-less tips on the back. A JD-9 nozzle allows spot spraying from the tractor cab or on foot with the hose on the reel. Jim Alwill shares this image of showy goldenrod plugs in a propagation setting where clethodim suppresses the cool season grass sod.Why we push back against invasive RCG: A 2007 image of a meadow at Nachusa dominated by plantain (Arnoglossom plantagineum) and culver’s rootA 2007 image with volunteer steward Kevin Kaltenbach in the same sedge meadow with those plantains in the distance.
Bill Kleiman, Julianne Mason, and Mike Saxton publish this blog. Bill's daytime job is director of Nachusa Grasslands with The Nature Conservancy. Julianne works for the Forest Preserve District of Will County. Mike Saxton works for the Missouri Botanical Garden at their Shaw Nature Reserve. We are looking for guest authors on various topics of grassland habitat restoration. Contact us with your ideas.
Great info, thanks. My experience using clethodim on RCG hasn’t been as positive, but this makes me want to give it another shot. BTW, I recently visited Clear Creek and was amazed by how much the riparian area has improved over the last few years — great work!
I used clethodim with a surfactant on reed canary grass in early April of this year. I have some forbs coming up in the patches of ECG that I had sprayed. The RCG is brown. I will spray again this fall and next spring to hopefully eradicate it. Jerry Whitledge
Kirk, I used 1 quart of RRSI Pacer which is a paraffin base petroleum oil and nonionic surfactant with 16 ounces of Volunteer which has 26.4 per cent Clethodim in 25 gallons of water which will cover 1 acre. The label asks for continuous agitation during application.
Jerry Whitledge
In areas where RCG does not have any competitors , can it be seeded after the fall application of clethodim? Or should I waste it with glyphosate in spring then again two more times till autumn and then seed with sedges and other grasses and praire plants? What advantage does adding imazapyr to glyphosate?
I am not confident about my advice. You could seed with the expectation that you will use clethodim every few years to help you establish a plant community. Or look at the Warrior Sedge posts and see what they did. The imazapyr will kill cotyletons emerging so you don’t want to plant seed within a year of using that. Part of the conundrum is seed is often preciously won, and you can’t be sure how much the RCG will come back from its seed and root stocks. If you spray clethodim while your seed is emerging the herbicide additives and surfactants can harm the delicate new sprouts.
grassland restoration network 
Great info, thanks. My experience using clethodim on RCG hasn’t been as positive, but this makes me want to give it another shot. BTW, I recently visited Clear Creek and was amazed by how much the riparian area has improved over the last few years — great work!
I used clethodim with a surfactant on reed canary grass in early April of this year. I have some forbs coming up in the patches of ECG that I had sprayed. The RCG is brown. I will spray again this fall and next spring to hopefully eradicate it. Jerry Whitledge
What were the concentrations of the ingredients being used and what were the mix percentages (either by volume or by weight) of those ingredients?
Kirk, I used 1 quart of RRSI Pacer which is a paraffin base petroleum oil and nonionic surfactant with 16 ounces of Volunteer which has 26.4 per cent Clethodim in 25 gallons of water which will cover 1 acre. The label asks for continuous agitation during application.
Jerry Whitledge
In areas where RCG does not have any competitors , can it be seeded after the fall application of clethodim? Or should I waste it with glyphosate in spring then again two more times till autumn and then seed with sedges and other grasses and praire plants? What advantage does adding imazapyr to glyphosate?
Thank you
I am not confident about my advice. You could seed with the expectation that you will use clethodim every few years to help you establish a plant community. Or look at the Warrior Sedge posts and see what they did. The imazapyr will kill cotyletons emerging so you don’t want to plant seed within a year of using that. Part of the conundrum is seed is often preciously won, and you can’t be sure how much the RCG will come back from its seed and root stocks. If you spray clethodim while your seed is emerging the herbicide additives and surfactants can harm the delicate new sprouts.