Vinegar as a herbicide

Discussion in 'Organic Lawn Care' started by Dchall_San_Antonio, Sep 4, 2003.

  1. Dchall_San_Antonio

    Dchall_San_Antonio LawnSite Senior Member
    Messages: 327

    Over on the cracked corn thread, Ducky1 asked about using vinegar as an herbicide. I suggested starting a new topic, so here it is.

    Vinegar is a dessicant type herbicide when used as a FOLIAR spray. It is not for use on the soil although the soil microbes consider vinegar to be a sugary food. If the vinegar can penetrate the plant's defense mechanism, it will likely show signs of wilting within a 10 minutes and become completely crispy dry in 4 hours. On a hot day it works faster. If you need fast topkill, say for laying sod, vinegar works pretty well.

    The vinegar I use is unmarked (so not for professional use) and has a strength of 20% acidity. It is the same as household vinegar except it is distilled to a higher acidity concentration. Household vinegar has an acidity of 5%. For many weeds (including Canadian thistle), the household variety is strong enough for 100% topkill. Repeat applications may be needed for weeds that return from the undead roots. For some plants, even the 20% has no effect. If you add orange oil (d-limonene squeezed from citrus peels) to the vinegar, the orange oil will help dissolve any waxy coating the plant might have and allow the vinegar to penetrate easier.

    I use vinegar on oxalis with impressive success. The overspray always kills my St Augustine (3 days later) so I have to shield the grass from overspray with a piece of cardboard. I have also used it on English ivy and on bermuda with no success at all.

    A vinegar product suitable for professional use is called BurnOut.

    One more thing about vinegar, especially the strong stuff. If you get any spashed into your eyes, you will be blind for several weeks to months. So as an organic herbicide, it has its dangers, too. If you wear a face shield properly you should be fine. I use a big funnel when carefully pouring the stuff into the sprayer, so there is no splashing. Vinegar is the most dangerous thing I use in my garden. Fortunately the smell of it naturally keeps my daughters away. To me it smells like grandma's salad dressing.

    Here is a website with links to the vinegar issues from all sides.

    Some of the links are relatively old. Some changes have been, for example the approval of BurnOut as a herbicide.

    And here is a USDA link from 2002
  2. GroundKprs

    GroundKprs LawnSite Bronze Member
    Messages: 1,969

    Now I'm gonna be a real pain, Dave. I thought the reason for organics was to reduce chances of toxicity in general on the earth. But Burnout has a DANGER label.

    Any licensed applicator should know the degrees of a label: caution, warning, danger. If I see a "Danger" label, I will immediately question the necessity of this product. It better do one heck of a good job on some problem, that a less toxic course of action cannot do. And vinegar just doesn't do that good a job from a commercial applicator's perspective.

    Seems it would be more productive to pull the weeds than to shelter all non target plants in the area from your vinegar. And pulling is a better long term control than burn down of surface materials.

    Research is good to have, but you need to watch the way it is presented. From the USDA report: "Canada thistle, one of the most tenacious weeds in the world, proved the most susceptible; the 5-percent concentration had a 100-percent kill rate of the perennial’s top growth. The 20-percent concentration can do this in about 2 hours." This makes it sound like vinegar will be a miracle cure for Canadian thistle. Unless you note that kill rate is on top growth. Why wait 2 hours? I can get rid of all top growth in 20 seconds to 2 minutes by hand pulling (with gloves on of course, LOL).
  3. Dchall_San_Antonio

    Dchall_San_Antonio LawnSite Senior Member
    Messages: 327

    I'm not at all afraid to talk about this. If I was I wouldn't have started the topic.

    Vinegar is the only dangerous thing I have in my garage. It is so much more dangerous than corn meal and molasses that I cannot even come close to comparing them. I limit my vinegar use to spot spraying with a hand sprayer on calm days, no broadcasting this stuff. No sugar coating from me on this.

    The danger of using vinegar is to the eyes of the applicator and to water systems. Personally I don't get the water systems warning, because vinegar dilutes out so darned fast it'll make your head spin, but it's there so you have to go by it.

    Whether the reason for organics is to reduce chances of toxicity in general on the earth might be a different thread topic. The reason(s) to go organic are as many and varied as there are organic gardeners, farmers, and customers. Does the lawn care professional have to know all the reasons why a client would want it? I don't think so. It might be nice to have for conversations with the owner, but I wouldn't put the owner into a hammerlock to pry the information out of them. I do believe the customers should be informed as to what they might be getting into with an organic program. They should know that the number of fast-acting organic weed controls is very few. They should know that vinegar is permanent on some weeds and temporary on others. They should know that the use of strong vinegar is potentially hazardous to the eyes of the workers should an accident occur, and they should know if you have a company policy against using it. They should know that the vinegar you use is much different from the vinegar they use in their salads. They should know that the only organic alternative to vinegar spraying is hand picking at a rate of $50/hour - or whatever. I am not suggesting you do anything dangerous or immoral. If you keep everyone informed and use proper training, I think you can mitigate the hazards and apply a product that will satisfy the customer.

    Here is a link to the MSDS from the manufacturer of BurnOut. sheets/mburnout.doc

    You can view the BurnOut labels at

    You'll have to rotate them and zoom in to read them. Since they are so hard to read, I've transcribed the text of the warning on the lable.

  4. GroundKprs

    GroundKprs LawnSite Bronze Member
    Messages: 1,969

    Sorry, Dave. All I can picture is the neighbors watching the guy with the face shield on the lawn, wondering to themselves: "Gawd, what kind of poison is he using now?"

    Soap and oil are great insect controls, but if you're doing a lot, you don't get a great taste in mouth if you catch a little drift. So most nurserymen will wear respirators when applying soap and/or oil. But me out on a customer site wearing a respirater? Think how that would agitate the neighborhood, LOL.
  5. Jimmy348

    Jimmy348 LawnSite Member
    Messages: 133

    I can see that one going over as good as a fart in church :D
  6. Dchall_San_Antonio

    Dchall_San_Antonio LawnSite Senior Member
    Messages: 327

    I suppose if you're required to follow the warnings, that mask would be a definite problem. Personally I wear shorts and because my sprayer is goofed up inside I get it all over my hands. So far no problems.

    But that's why the forum is here. Maybe someone has a good solution to this.
  7. GroundKprs

    GroundKprs LawnSite Bronze Member
    Messages: 1,969

    Dave, when you are a commercial applicator (or even any applicator), the pesticide label is THE LAW. No one is going to look at you in your shorts. But if an inspector sees me without proper PPE, as stated in the label, I'm fined, or lose license if it's a real bad, repeated flaunting of the label.
  8. Ozi_Brisbane

    Ozi_Brisbane LawnSite Member
    Messages: 27

    I tried vinegar on the weeds that have sprouted between the cracks of the paving in my backyard.

    Lo and behold! The younger weeds were drooping by next day and the more mature ones weren't looking so bright and bushytailed anymore :D

    I only used household grade white vinegar. So cheap as can be. And it works just as good as the more expensive weed control stuff that is out there.

    I am impressed. I'll use it from now on to deal with my customers weeds. They'll love me for it. In fact, one is already all hyped by the idea of me not using ghastly chemicals in her garden.

    I think I'll add Natural to my business name from now on :)
  9. Dchall_San_Antonio

    Dchall_San_Antonio LawnSite Senior Member
    Messages: 327

    Thank you for trying vinegar and reporting your findings Ozi. Are you allowed to use it commercially in the land of Oz?

    If you can mix in some orange oil (d-limonene), it really enhances the speed with which it works. The orange oil is a strong organic solvent that dissolves any oily or waxy coating the plant might protect itself with. Then the oil and vinegar work on drying out the plant. I mix 3 ounces of orange oil to a gallon of vinegar. The orange oil will float on top so you also need to add a couple ounces of liquid dish soap to relax the surface tension of the water and allow the oil to mix in. Then I keep shaking my hand sprayer. Also, you must clean the sprayer or the metal parts inside will corrode. Vinegar has a pH of 3.0, interestingly the same as Coca-Cola.

    When I worked for the Air Force I worked right across the partition from the captain who was evaluating orange oil for military applications (cleaning). His finding was that it was probably too strong to use in offices but could be used industrially if a way was found to recycle it. Apparently our normal method of dumping industrial waste at a remote site on base wasn't good enough for orange oil :) This was because even though the orange oil became dirty, it still continued to work against everything in the soil (including previous industrial oils and waxes deposited in the soil). This resulted in leaching of the previous contamination to lower levels in the soil - which is a bad thing. So since orange oil can be filthy dirty with all sorts of contamination, it doesn't lose any of its cleaning ability. So you can dump dirty parts in a dirty solution and the dirt on the part will dissolve but the dirty solution will recoat the parts with dissolved dirt. Anyway, it's too late to make this long story short, but we did find a way to filter it and reuse it. Now it is used to clean soot and everything else off of jet engine parts.

    And I always like to get this reminder in when I can. It seems I can't say this enough on other forums:

    Vinegar is a foliar spray, not a soil drench.
  10. Ozi_Brisbane

    Ozi_Brisbane LawnSite Member
    Messages: 27


    My state department of primary industries is very happy with the use of vinegar in the domestic environment. They said, go for it!

    So I am!

    I suggested the use of vinegar to a customer today, and she loved the idea because she uses vinegar for household cleaning and is a bit of a natural products freak anyway. I hope I've won her heart with vinegar :)

    I'll investigate the orange oil addition, as soon as I can find some!


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