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ladyslppr

Roundup worked on Garlic Mustard

ladyslppr
15 years ago

Over the past few weeks I sprayed a lot of the Garlic Mustard in my woods with Roundup (actually a generic version which was cheaper). I was hoping I could spray and kill the Garlic Mustard without damaging the native woodland plants that are still hanging on in the same areas. Now, a couple of weeks later, I am able to see that my approach apparently worked. I tried to spray at the time of the year when Garlic Mustard was actively growing but few of the native woodland plants had emerged from the ground. This spring that meant spraying in mid-April, or even sooner if I had gotten around to it. When I mixed the Roundup at the recommended strength, I saw no results for several days, so later spraying was done at the stronger strength recommended for shrubs. Now, a couple of weeks later, I see that both dosages worked. In several places I have dead or dying Garlic mustard with natives like Wild Geranium, Mayapple, False Lily of the Valley, Virginia Creeper, Red raspberry, and Blackberries emerging in the middle of the dying GM. Apparently spraying the GM, and unavoidably spraying a fair amount of Roundup on the forest floor, didn't hurt the natives that had not yet emerged from dormancy. It doesn't seem to have done too much harm to the blackberries either, although I sprayed a lot of balckberry stems. Part of the reason that I chose to spray was that a lot of the GM was growing amid blackberry canes and was hard to get to, and would have taken a lot more time that I could devote to pulling. Another reason was that pulling disturbs the forest floor and I suspect encourages the next generation of GM. there are a few natives that emerged too early and I had to avoid, including violets and bee balm (Monarda didyma). Overall, I am happy with my results. I would not have gotten nearly as much of the woods cleared of this year's crop of GM if I had only pulled.

Comments (14)

  • linda_schreiber
    15 years ago

    Thanks so much for all the detailed information! This is wonderful. If you could, please update us later as to how things have worked out.

    Truly appreciated.... Thank you.

  • davidl_ny5
    15 years ago

    "Have no idea where the seeds came from, ..."

    I have read that deer may spread them -- the seeds catch in their coats and drop later. The explosion in the GM population may be related to the explosion in the deer population.

  • amelanchier
    15 years ago

    Well, on Monday I went down to Goat Island by Niagara Falls, where there are no deer, and the forest understory was almost completely infested with GM. Fortunately, there were still some pockets with blooming trout lilies, mayapples, & trilliums! But who knows how long it will be before they are smothered beneath the invader.

  • krenster
    15 years ago

    Can I ask what generic version of Roundup you used? And where you got it? I just discovered the weed infesting my forest is GM and need to take action this week!!!

    Thanks

  • bob64
    15 years ago

    I bought some generic "Roundup" (glyophosphate) concentrate once from a company that sells grass seed in bulk to landscapers. Maybe some place like that near you would have it.

  • ladyslppr
    Original Author
    15 years ago

    I'll have to check the brand on the label when I get a chance, but what I used is a concentrate of 41% glyphosate. I mixed with water at about the concentration recommended for herbaceous plants (3 oz per gallon), then again at the higher concentration recommended for shrubs (6 oz per gallon). Both worked fine so I'll use the lower concentration next time - it kills but is slower.

    By now, most of the native plants in my woods have appeared, so I won't be spraying again this year. Even in areas that appear to be nothing but garlic mustard, there are often small natives growing. I want to kill the Gm and leave the natives, so I spray in early spring when the garlic mustard is growing but the natives are still dormant. I have also successfully sprayed on a warm day in late fall - it toook a long time for the garlic mustard to die, I think because of the cool weather, but it did die. Garlic Mustard stays green all year which probably gives it an advantage in growing faster, but also provides the opportunity for us to spray it while the native plants are dormant.

    At this time of the year I either pull the garlic mustard, or this year I plan to use the weedeater to cut the tops of the Gm when the flower buds appear (right now here in central PA). I hope this will reduce the number of seeds produced. Garlic Mustard gets much taller than most of the native plants are at this time of the year, so I should be able to take its head off without harming natives. I'f i would have been on the ball earlier, I would have sprayed it all.

  • bob64
    15 years ago

    I recently cut down a lot of GM as it started to flower since there was too much to ever pull it all by hand. I'm hoping that this helps. I think I should follow your lead in the future and do more spraying in the off season since I won't ever get ahead of it otherwise. Glyophosphate is supposed to be rendered relatively harmless when it hits the soil so I doubt merely touching the soil suppressed any of your natives.

  • ladyslppr
    Original Author
    15 years ago

    Another nice advantage to spraying Garlic Mustard in early spring is that there is not as much to do in the garden as there is later in spring, so I have more free time to devote to Garlic Mustard control than I would if control had to be done only in May. I bought my generic Roundup at Lowe's, and I bet most garden centers, Walmart, etc. would have something similar.

  • catherinet
    15 years ago

    Wherever we've pulled out honeysuckle, we now have garlic mustard everywhere (plus baby honeysuckle). I think this is going to be a futile, life-long struggle. We have 33 acres and just can't keep up.
    We may just eventually have to accept that this is evolution and quit fighting it.

  • myrtle_59
    15 years ago

    FYI - I just learned today that spraying roundup on a sycamore tree can kill it while it will not hurt most trees with thick bark.

  • ladyslppr
    Original Author
    15 years ago

    catherinet,
    The invasion of wiidlands by Garlic Mustard and Honeysuckle is not evolution, it is destruction of the ecosystem by human intervention. If Garlic Mustard (or any other non-native plant) had naturall invaded North America when the continent was in an undisturbed condition, it would have had to spread through mostly intact plant communities and would have had to spread on its own, without human help. It would have moved at a very slow pace, and insects, diseases, and other forces that control natural plant populations would have slowly adapted to feed on Garlic Mustard. As it slowly spread across the continent, it would have become part of the native flora like hundreds of other species have done, and it wouldn't have cause any problems. As it turned out, Garlic Mustard was introduced by man and has spread rapidly in disturbed areas, then spreading into less disturbed areas of woodland. Its spread has been greatly helped by mankind, as have the invasions by dozens of other plants, and the problem continues today. I am sure that there are a dozen plants being sold and grown in gardens, or introduced as weeds in imported seed or soil that will, in thirty years, be just as bad as Garlic Mustard. We never learn.

    It is possible to get ahead of invasive poants on your property, however. Take a look around the woods near you. You can probably find some areas where few invaisve plants are growing. These areas are stable with well established native plant populations, and eventually you can make your woodland into one of these places. one of the first steps is removing invasive plants, but adding native plants should not be far behind. I think as you're working to get rid of invasives it is important to be planting natives at the same time because removing invasives is frustrating and you sometimes seem to lose ground faster than you can gain it. Growing plants, on the other hand, tends to move in the right direction once you get the plants established successfully, and makes a nice contrast to plent removal.

  • myrtle_59
    15 years ago

    The plant who fears my and my roundup most, is poison ivy. Other plants may offend my sensibilities in one way or another but poison ivy is the only one that reaches out and touches me!

  • fandango52
    8 years ago

    @catherinet - I've been removing honeysuckle for the past several years. I see the same thing as you... each time I remove one I get hit with garlic mustard, lonicera, etc. Over the last several years I noticed something else though... trees. I started noticing red oak, white oak, and shagbark hickory saplings coming up among the garlic mustard where the honeysuckle once stood. The problem was... DEER. The deer in my part of Ohio eat the new growth on hickory and oak saplings each year and they aren't able to grow fast enough (and eventually die). I've been keeping track of the places where I've removed honeysuckle. I then watch for new, desirable trees, and fence them from the browsing deer. Eventually, the trees will provide a dense canopy that the honeysuckle had been providing. This dense canopy will help drown out the garlic mustard and other nasties. I didn't have a single shagbark hickory on my land (before I started removing honeysuckle and protecting the shagbark saplings). I only had gigantic mature oaks and not a single sapling or younger tree before protecting them from the browsing deer. It's not that I don't battle the garlic mustard too. It's just that it's easier to battle garlic mustard with a dense canopy and dense understory on your side. I'm focusing mainly on the canopy and understory first. You're right tho... lifelong battle... may not win. Still nice to be out there enjoying the battle.

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