Question
Will vinegar kill weeds in the garden (Bermuda grass...ect)?

Answer
95 percent of the lawns in this country are soaking in things like Round-Up and Weed-B-Gone.  To rid your lawn of weeds, two user-friendly contact killers are gaining popularity: Vinegar and Pelargonic Acid.

The U.S. Government has actually studied this problem.  Back in 2005, USDA scientists did an experiment to test Vinegar as a Weed Killer.

You can access the results for yourself at:

www.ars.usda.gov/research/publications/publications.htm?seq_no_115=176567.

Their basic work was to test different strengths of Vinegar on grass.  They picked a field in Oklahoma and went spraying.  Broadleaf and other weeds, wild grass, crabgrass, carpetweed, evening primrose -- all these weeds were sprayed with Vinegar.

Know what they discovered?

Vinegar worked better on broadleafs than grass-type weeds.  A 5 percent Vinegar solution (95 percent sugar) actually wiped out 90 percent of the wild Evening Primroses.

84 percent of the broadleaf weeds was eradicated with 10 percent Vinegar.

Remember that next time you run into someone who tries to tell you that Organic weedkillers don't work.  These government experiments should rest that case.

Note: Supermarket Vinegar is only 5 percent strength.  That's the stuff you use in your kitchen.  It's still 95 percent water.  Even at full strength, your kitchen Vinegar is not going to do much damage to weeds.

So when your hear people talk about killing weeds with Vinegar, remember that.

The Vinegar worked best at 20 percent, a concentration sold in farm supply stores that is strong enough to burn your skin.

Vinegar is so earth-friendly.  After it's done killing Crabgrass, Canadian Thistle and Dandelions, it disappears.  You can mow and breathe to your heart's content; your children and pets can roll and play; no one gets sick.  Ever.  And this is why it is not BANNED in the State of California, the State of Maine, the commonwealth of Canada or any other region of the world.  You can't say that about Round-Up or Weed-Be-Gone.

Cornell University did another experiment.

Researchers tested Vinegar-based weed killers and compared them against the infamous but best-selling Roundup(glyphosate).  Results for Nature's Glory (25% Vinegar), BurnOut Weed and Grass Killer (25% Vinegar, with a few organic kickers to strengthen its impact on weeds), and supermarket Vinegar (20% and 5%) were charted.

You can see an analysis of some of these weed-killers at the North Carolina State University website
(www.ces.ncsu.edu/chatham/newsletters/growergram).  

Some tests found Vinegar worked best of all when they heated it first.  You'll find lovely photos taken of a test of Acetic Acid sprayed on Canadian Thistle and Dandelions at www.organicagcentre.ca  Dandelions survived, the Thistle did not.

Pelargonic Acid -- another contact weed killer found in apples and grapes -- kills broadleaf weed foliage almost instantly.  That includes Dandelions, Canadian Thistle, and Pigweed.  Companies like Bioscape (bioscape.com) and Mycogen (Scythe Weed and Grass Killer) sell strong
herbicides based on Pelargonic Acid.  

Weed-killers work on contact, burning green weed foliage rapidly.  But they don't kill roots. On an Annual or a weed without a tap root, that's not a problem.  But with Dandelions, underground bulbs and wildflowers growing from tubers, it is often just a matter of time before the plant recovers and is sending out long stemmed fluffy white seedheads to blow across the plain towards lawns everywhere.  Yes, ONLY THE LEAVES are killed by Vinegar and Pelargonic Acid; anything underground is safe and protected.  The same Dandelion must be sprayed at least 3 times before you see a difference.  And remember, contact weed killers are also fatal to grass, flowers and vegetables.

One researcher found that spraying once a week for 3 weeks was the answer for tough weeds with thick roots.  For some people, hand digging with a Dandelion Fork may be easier, so long as you get the whole root.

There are other weed killers, using things like Clove Oil or other formulas.  They are too recent for me to tell anyone how well they work:

'Matran EC Herbicide' is USDA Organic certified.

'Bioganic Weed and Grass Killer' (10% Acetic Acid) and 'EXEMPT' are new enough that they are still awaiting EPA approval for sale in many states, possibly in your neighborhood; both are billed as organic by Biocontrol Network (www.biconet.com/lawn/matran.html).

These "Contact Weed-killers" are for weeds outside your window today.

"Pre-emergent weed-killers" will keep weeds from returning after the original weeds have been eliminated.  

For this, your timing is excellent.

Believe it or not, right now is the perfect time to put down Corn Gluten Meal on your lawn.  Researchers at Iowa State accidentally discovered its pre-emergent weedkiller properties after Corn Gluten Meal kept seeds from sprouting during research on other things.  They have a patent on it.  Let me know if you need to know where to buy it in your neighborhood.

You can also get it on the internet.

Dandelions are perennials.  So any that were growing last year in your lawn will still be there unless you dug them up or killed them.  Corn Meal Gluten will work on Dandelion seeds that are getting ready to sprout.  But to get the ones that are there, you'll need one or more of these other measures.

Are you saying you have a weed problem, Bryson?  I feel your pain.  For reasons I will be happy to go into if asked, dousing your lawn with anything made by Scotts, Ortho, Bayer or any of those other multinational pesticide specialists will give you even more problems.  If you think weeds are a problem, try dealing with some of these others.

But let's look at your grass.

Ooops... we can't do that, you did not describe your grass.  OK, no problem, let's look at your weeds and how to send them packing.

First, note that lawn grasses and weeds do not like the same kind of soil.  Weeds thrive in Acid soil.  Turfgrass prefers Alkaline soil.  A soil test will give you a good pH read.  It can also explain why your grass is not strong enough to choke out all those weeds.  At the very least, a big dose of lime in the soil right now will raise the pH enough to weaken weeds while your grass builds up.

When you mow your lawn this year, leave the clippings on the grass; this returns nutrients to the soil and builds up a nice rich topsoil.

The Better Lawn and Grass Institute
(www.turfgrasssod.org/lawninstitute/guide.html) points out: 'Proper mowing, watering, and fertilizing practices develop a lawn that needs less chemicals to control weed, insect, and disease problems.  This is particularly true when you have established your lawn with improved grass varieties.'

What kind of grass is growing between the weeds?  You cannot grow a first rate lawn from second rate seed.  Rye? Fescue?  Bluegrass?  Bentgrass?  St Augustine?  Zoysia?  It's important to know, because the your grass determines mowing height.  Check The Lawn Institute website above or Organic Lawns www.organiclawncaretips.com) for the best mowing height for your grass variety.

There are plenty of bad things you can buy for your lawn, and they are popular because marketing is so effective and very, very profitable.

Treating your lawn with lime and a good Nitrogen fertilizer is the best prevention for weeds.  Healthy lawns with a good pH and lots of Nitrogen (the first number on a bag of fertilizer) don't make happy homes for alien species.  Milorganite hapens to be one of my favorite fertilizers.  It's very high in Nitrogen and releases nutrients for some time after application.  This is the perfect time of year to fertilize your lawn.

Weeds can be a complicated problem.  But there are solutions.  If you act right away, you can solve your weed problems cheaply and safely.

I apologize for the long and painfully detailed answer here.  I hope it was worth waiting for.