Garlic Mustard Update

Thanks again for following our adventures at The Springs!

The Scuppernong Springs Nature Preserve, which encompasses the nature trail, is overrun with invasive species including: buckthorn, garlic mustard, spotted knapweed, phragmites and many others. We have made some progress over the past 2.5 years and take heart in that, but there is a long way to go. This past summer I made a commitment to stop using toxic foliar sprays to control invasive species and the challenge remains to come up with effective and efficient alternatives.

Garlic mustard is a biennial weed and the first year growth is lush throughout the nature preserve, especially in areas where we have cleared buckthorn, girdled black locust or otherwise increased the amount of light reaching the ground. Here are a few images of garlic mustard on the south end of the loop trail.




In the old days, I would have sprayed this with glyphosate, aka RoundUp. Now, what to do? I have been working with the DNR to try a non-toxic herbicide and it has taken some time to acquire a sample since the product was new for the DNR. Don Dane navigated the procurement process for me and got 1 gallon of EcoExempt HC, which has the active ingredients: 2-Phenethyl Propionate (extracted from peanuts) and Eugenol (clove oil). There seems to be a lack of research available on 2-Phenethyl Propionate as reflected on this site as indicated by it’s “no available weight-of-the-evidence summary assessment” for key toxicity indicators. This herbicide is less effective in cool weather, and, given the cost, I’m hesitant to use more this fall unless I see excellent results in the area I sprayed yesterday. Speaking of the costs to fight invasive species, I thought this piece from Dow AgroSciences made some valid points contrasting the various options available e.g. what uses more energy and produces more environmental harm: spraying with an herbicide like glyphosate, or transporting 10 volunteers to pull weeds?

It looks like I may be too late this year to attack the first year garlic mustard and we can expect carpets of this weed to flower everywhere throughout the nature preserve next spring. We’ll have to decide whether to continue using EcoExempt, try an acetic acid based herbicide, mow with a brush cutter, or pull the weeds before they set seed.

This past Thursday and Friday (Nov. 7-8) I spent some time stacking buckthorn at The Springs and at Ottawa Lake campground site 335. I’ve been working on the northeast side of the trail in the area around signpost #1 and #2 and recently laid down the buckthorn that surrounded the brush piles I had started. On Thursday I added all the newly cut buckthorn to the existing piles and they are ready now to burn.

It was a cool day and the wood was wet to handle but the sun finally came out revealing fall splendor.





A parting shot.


I spent 3 days clearing brush and thinning the trees around Ottawa Lake campsites 335 and 334 and this wood needs to be piled. Yesterday, under beautiful skies…



… I started, and I’m putting the big pieces that would make good firewood into separate piles.

Sunset at Ottawa Lake.








See you at The Springs!

7 thoughts on “Garlic Mustard Update

  1. Fabulous pictures!
    What is the problem with glyphosate on garlic mustard? It binds to organics and clays on contact with the soil where it is eventually broken down to CO2 and H2O, so it doesn’t migrate in the soil. I’m aware of the problem with aquatic organisms which are sensitive to the surfactants in it but the aquatic versions look relatively safe for them.

    By the way, Now is the best time to treat garlic mustard and dame’s rocket w/ glyphosate, at least until the ground starts to freeze. They are easy to see now since they stay photosynthetically active and there is little to no collateral damage since everything is mostly dormant now.

    Best regards,


    • Hi Nathan. Per this article there are still some doubts about the safety of glyphosate. Here too…

      I’m not 100% sure that it is safe to use.

      Yes, now is the time to hit garlic mustard and I should have made more effort to be in a position to take advantage of it. I might try to an acetic acid based herbicide before it gets too cold. The EcoExempt I sprayed last Friday was showing some signs of impact today, but not much… it’s too cool.

      • Paul, I hope you are careful with the use of acetic acid. Concentrations of 11% or greater can cause skin burns and permanent corneal injury. I am a chemist and work with some really dangerous chemicals in the controlled environment of the laboratory but as a general rule I don’t like handling dangerous chemicals in the field like the more concentrated acetic acid. Please protect yourself and be careful!

  2. I don’t have anything to add to this learned chemical discussion. I just wanted to mention that in my frequent drives to Washington DC, through Indiana, Ohio, Pennsylvania and Maryland, I am seeing an EXPLOSION of phragmites. Don’t know if I just never noticed them before….I tend to doubt it. But they are friggin coloniziing so many of the roadside ditiches along I-80.

    • Amen brother! “Friggin explosion” is a good description of it all. A few years ago I too visited out East, in particular Maryland and New Jersey. I saw the same sickening sight you saw. And much more. As I had become more knowledgeable and adept at identifying invasive species, the sheer number of aggressive, invasive species and the density of them colonizing roadsides and out in natural areas was just astounding to me. I feel this is a huge, under-appreciated, environmental problem. I have frequent discussions with my neighbors who look out at the “natural” buckthorn-covered shrub jungles near our homes and they tell me how much they enjoy living in and looking out at these areas because of their love of nature. I get a lot of blank or surprised looks when I tell them about the environmental degradation they are really seeing. We can set aside natural areas but if they all just grow up into crap, what have we really accomplished. Sorry to be such a downer but as someone fighting in the trenches against these forces, it is a problem that preys on my mind daily as I’m sure it does with you and Paul.


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