Hi all,
I've been looking for a "friendly" herbicide…I don't really know if there is such a thing.
I'm curious as to whether any of you have used the vinegar for weed control, and if so, what you think of it?

I have used regular 5% vinegar that I diluted and it did kill most of the weeds where I poured it. This site says to use 10% undiluted. Considering the affect mine had I am sure the 10% would be very effective. This site is strictly organic recommendations so I'm sure it's safe.

http://www.dirtdoctor.com/Vine...

http://www.dirtdoctor.com/Vine...

Thanks so much for your response, and the links! Especially the uses and misuses. Very informative! I had heard something about the orange oil increasing it's killing power.
I think I may have to give it a try.

Ain't nothing as eco-friendly as hours on our knees with a screwdriver.

Well, unless it's 2 inches of coarse mulch.

I suspect that vinegar is not very selective and would kill flowers and crops as easily as weeds.

If you use vinegar often, you would probably acidify your soil. Maybe counter that by using ammonia sparingly, occasionally, as a spot treatment for weeds in the area that was acidified by vinegar.

Hi RickCorey! You give me something to think about there! But I'm also thinking that I'd have to use tons of vinegar in a specific area to change the PH of the soil…AllI'm wanting to do is kill/knock back some prolific weeds such as dollar weed, nutsedge, pusley, etc., not only in beds, but also 'lawn'…Spot treating.

" Maybe counter that by using ammonia sparingly, occasionally, as a spot treatment for weeds in the area that was acidified by vinegar."

Can you clarify this? Are you speaking of ammonia as also being a weed killer? Or as an addition to a fertilizer to counteract any PH imbalance? I'm not sure I understand.

It was just a thought tossed out without much thought behind it. That ammonia would be no worse for surrounding plants than vinegar, and I would offhand expect it to be just as good a weedkiller.

(And i'm planning to use small squirts of diluted ammonia to kill slugs next time we have a bad slug year, so why not use it on weeds? As I said, i didnt give it a lot of thought)

I was thinking that vinegar (acetic acid) would acidify the soil instantly, and hence would need some counter-acting base like ammonia. After all, people worry about pine needles and coffee grounds acidifying their soil, and 5% acetic acid is a MUCH stronger acid than either of those.

But you could use limestone instead of ammonia.

>> Are you speaking of ammonia as also being a weed killer?

I'm saying that it is probably about as good as vinegar as a weed killer, since neither one is at all selective.

P.S. Ammonia IS a fertilizer, pure N. But in excess, like acetic acid (vinegar) it will indiscriminately kill any plant.

I think that both of them are somewhat unsuitable for use as a weed killer. Better to get a weed torch, or your Bernz-o-matic propane torch set to needle jet and burn just the weeds. That would be more selective than pouring vinegar.

If there turn out to be yellowed holes "burned" into the lawn where you spot-treated with too much vinegar, or from using it too often in the same spot, you might counter that by alternating one non-selective plant poison with another (ammonia).

>> Or as an addition to a fertilizer to counteract any PH imbalance?

I don't think any fertilizer available anywhere would be as acid as 5% vinegar. Googling, I see pH values ranging from 2.4 to 5. I would easily believe 3.5 to 4 - after all, Coca-Cola is around pH 2.

I question the ecological value of using something totally nonselective to kill weeds. Except for lawn grass, almost any plant you cultivate will be LESS tough than a weed, so you should expect to kill more desirable plants than weeds!

But maybe not, I haven't read those links yet.

At least vinegar would be toxic in the soil for less time than salt. One person wanted to kill weeds by pouring salt on them! Because she thought RoundUp was too toxic!! That was known to ancient Greeks as a way to make a field totally infertile "forever".

(I guess they didn't have much rainfall in ancient Greece. Where there is enough rain and drainage, a salinized field will eventually flush clean, and the fields downstream will die instead. Vinegar isn't THAT bad. In time, it will be oxidized away by soil microbes after it's dilute enough. And you can neutralize the acidity if you don't want to wait.)

I understand the desire to use a bio-degradable weed killer, and vinegar is bio-degradable.

However, like salt or RoundUp, vinegar (acetic acid) is toxic to plants.

Like salt, vinegar is toxic to all plants except a very few.

RoundUp is somewhat selective (although many weeds are developing a tolerance for it.)

Unlike Roundup and most other other "chemical" herbicides, vinegar will also kill any soil microbes right where you pour it, unless they are very tolerant of acid. I don't think any soil fungus would tolerate pH 4. But they would grow back after the vinegar is diluted.

Rick I would agree with you that all chemical should be used with caution. But you are throwing out a lot of negative information about vinegar, using a words like, probably, offhand expect , thinking that. These are not words that give me a lot of confidence in what you are saying. You offer no evidence other than what you THINK. I have been reading about vinegar as a herbicide and the only negatives I have found so far are, that may not be effective on some weeds, it is only a contact killer and does not get the roots and it can be physically hazardous ( burn the skin) in high in the higher concentration (20%), which is why all chemicals should be handle safely. The links that I gave terrafirma recommend no more than 10%. You said "I don't think any soil fungus would tolerate pH 4". Where is the evidence that vinegar would have this effect.
If found this research by Swedish Agricultural University: "Addition of 24 % vinegar to a peat soil decreased the pH of the soil from 7.3 to 5.6. However, after 48 hours the pH values
of the soil returned to 7.0-7.5"
That is an extreme concentration, far in excess of the recommended 10%.

Thanks to you both…Much food for thought.
Yes, I do agree that ALL chemicals, if used, should be used with a great deal of caution. And my "go to" for 'mental therapy' is getting in to the garden and physically pulling
those buggers! But there are also times and places where I had thought a more friendly 'chemical' approach may come in handy, such as cracks in concrete drives, patios,
and yes, even areas of lawn. lawns!
I'll certainly be doing more research, and also using sparingly…Spraying, not pouring...
Your insight has been most helpful...

Jay, you are compleely right about this:

>> But you are throwing out a lot of negative information about vinegar, using a words like, probably, offhand expect , thinking that.


>> Addition of 24 % vinegar to a peat soil decreased the pH of the soil from 7.3 to 5.6. However, after 48 hours the pH values of the soil returned to 7.0-7.5"

If that also applies to much less organic soils like heavy clay and sandy loam, it would knock down my concern that using enough of a non-selective plant poison like vinegar would make soil too acid.

And since I haven't tried it myself and DON'T know that acidifying soil is a real concern, I shouldn't raise it any more than mentioning the possibility once in passing.

>> Spraying, not pouring

That sounds smart.

My own 2 cents worth of an isolated usage of vinegar:

I had a small area (about 5 ft x 10 ft) full of weeds that I never wanted (and still don't!) anything to grow in ever again. And a small note: we have very heavy clay soil in that area. So. I liberally sprinkled the area with table salt, then soaked it all down with straight, undiluted vinegar. Definitely killed off all the weeds and lasted for about a year. The following year, the weeds were happily filling up that same area. Now perhaps the winter snow and rain leached out the salt and vinegar. But it was definitely a short term effect in my case. So I look somewhat askance when I hear people predict dire consequences from using either vinegar or salt. However, it WAS a one time experiment in a very limited area.

Thanks so much Woofie, for sharing your experience with the vinegar…Your 2 cents are worth a bit more, as far as I'm concerned!
I'm very interested in others experience using this…Much obliged... And it's nice to meet you!

As I said, tho, it was a one time trial. Although I did use a similar mix to spray around the perimeter of my dog's kennel at that same time. The spray was somewhat diluted, but still helped keep the weeds down. I opted for the vinegar and salt mix because my girl would rub against anything I sprayed around her kennel, and I was very nervous about using other chemicals.

I can confirm that chemical weed killers do not work. I am not so sure that they do not work on all weeds anymore because of the plants but I think environmental codes have demanded they remove some of the more dangerous chemicals. I sprayed poison ivy with Roundup and it acted like I gave it some fertilizer.

I use the vinegar and salt and that works. I have a long hot sun all day walkway that I cannot pull the weeds between the bricks without getting heat stroke.

I pour a box of salt followed up with vinegar poured between the bricks. That keeps them down for about a month or two if we do not get a lot of rain but the quake grass, wild oxalis, Purslane comes right back before summer is over.

So if pouring a layer of salt and vinegar chaser does not make that crack sterile for life I do not see how it could possible hurt in the soil anywhere else.

Okay here is more proof. This was a property that had not been cared for for years because the owners were elderly and could no longer care for 4 acres. I had a very large job ahead and I wanted to do it with as little hired help as possible. So I started with areas. This was outside the back door area that I poured (yep poured 3 bottles of vinegar, and sprinkle one box of salt, and covered with cardboard. Had lots of cardboard boxes from the move. Over that cardboard I put all the Fall leaves from the yard. The following Spring I planted my hosta that I had moved from the old house that were in pots all winter waiting for their new garden.

You can see there were still some weeds that did not care if they were vinegar, salt, cardboard covered they were coming through.






and so you can get a real feeling of how big this area is nothing like a winter pic to show

How very disconcerting!!! Thanks for sharing!