Did You Know? Vinegar Can Replace Roundup


In today’s Did You Know? post, I thought that we would look at an alternative to Roundup. Roundup’s active ingredient is glyphosate and it is being applied at an alarming rate in the U.S. and abroad. According to the EPA, 135 million pounds of glyphosate were applied in 2010. That’s just the pounds of active ingredient glyphosate. Generally speaking, Roundup is 41% glyphosate and 59% inert ingredients. That’s a lot of chemical being applied to the 1.9 billion acres of soil in the contiguous United States.

vinegar can replace roundup

Photo courtesy of myghostorchid.com

Here’s an easy alternative to Roundup and all of the toxic ickiness that comes with it: vinegar. Yep, good old fashioned vinegar; the same stuff that you use to pickle cucumbers and you put on cabbage to kick it up a notch. Vinegar is acetic acid and the “normal” type that you get from the grocery store is comprised of 5% acetic acid. There is a horticultural type that is 20% acetic acid and it is much more expensive…to the tune of $29 a gallon versus $5 or under for “normal” vinegar. Either one will work but the 20% type will work a bit faster and be capable of killing perennials and more established plants.

Here’s my disclaimer: vinegar is a non-selective herbicide just like Roundup; it will kill whatever it comes into contact with so be sure that you apply it only to the plants that you want to get rid of. Don’t apply it on windy days either…it can drift just like Roundup too. Another caveat: be sure to rinse out your sprayer after each application to avoid damaging the internal parts. Spray clean water through the sprayer to ensure that all of the bits and pieces in the nozzle are free of vinegar residue.

So here’s the magic formula: Full strength 5% vinegar + a tablespoon or two of dish soap. Spray on the weeds and wait overnight. They should be browning up by the next morning. If you have particularly onerous weeds, you can apply again as soon as you see regrowth. Add table salt to the mix for more killing power…a tablespoon per gallon should do the trick.  You may also need to invest in horticultural vinegar for those hard to kill weeds. If you use horticultural vinegar, be very careful and wear personal protective equipment to protect your eyes, nose and skin. If you are killing young weeds that are primarily seedlings, you can dilute the 5% vinegar with water to make it go further. Experiment and try different concoctions…what do you have to lose?

If you like what we’re doing here at Mid-Atlantic Gardening, please subscribe to the website to receive updates to the latest posts as well as to be eligible for our subscriber giveaways. You can subscribe by joining our e-mail list on the top right of this page. Thank you for your support! If you have experience with using vinegar instead of Roundup, leave me a comment below or e-mail me at stacey@midatlanticgardening.com. Don’t forget to like our Facebook page and follow us on Twitter! Happy gardening!

Pests and Diseases: Glyphosate Damage to Trees


Today’s Pest and Disease post is a little different than some of the other topics that we’ve looked at such as gloomy scale or aphids. Today we are going to look at something that you may not even think of when you’re spraying weeds in your garden: glyphosate damage to trees. In case you’re not up on your chemical names, glyphosate is the active ingredient in products like Roundup and RazorPro. We have been told for years that glyphosate is biodegradable and has no residual impact on the soil that it touches. More and more, people are beginning to realize that may not be the case.

glyphosate damage to trees

Photo courtesy of Ohio State University

Dr. Hannah Mathers of Ohio State University has led the research on determining if glyphosate is responsible for cankers on trees where the chemical has been applied. The cankers resemble frost cracks that can occur during cold temperature extremes. The difference is that frost cracks generally appear on the south side of the tree whereas “glyphosate cankers” can occur on any side of the tree. The long and short of her research is that glyphosate is accumulating in the phloem of the trees and causing cankers and ultimately death. The death is a slow one as microorganisms move into the canker and set up shop. Glyphosate may not be the cause of death in the end but it is what allows the microorganisms a chance to kill the tree.

So how does the glyphosate end up in the phloem of the tree? It generally occurs one of two ways: the first way is by applying the herbicide around the base of the tree and having it come into contact with the trunk. You may not be trying to spray the trunk directly but if there are weeds at the base of the tree, you may inadvertently spray the trunk. The second way is through killing the weeds that grow within the root zone of the tree. That is, after all, probably why you are spraying herbicides to begin with. When these weeds die, they exude a small amount of the chemical into the soil which can then come into contact with the roots of the trees. The roots take up the small amount of glyphosate into the xylem of the tree but as it is transported throughout the tree, it ends up being stored in the phloem. Research indicates that the glyphosate can build up in the phloem for years and continue to cause problems for the tree for a long period of time.

Dr. Hannah Mathers has found that using glyphosate products that contain a surfactant exacerbates the problem. Surfactants are added to many pesticides to allow the chemical to “stick” to the target pest. The stickiness that results also allows the glyphosate to adhere to the trees if they are inadvertently sprayed. Unfortunately, virtually all of the homeowner versions of glyphosate contain surfactants.

So what can you do to avoid glyphosate damage to trees? MULCH! While I certainly don’t advocate the practice of mulch volcanoes, a 3″-4″ layer of mulch under your trees will keep most of your weed problems at bay. For the weeds that appear, hand weeding is going to be your best option. Also, consider planting perennials under the trees. A groundcover of plumbago (Ceratostigma plumbaginoides) will thrive in sun or shade and will form a dense mat that is almost impenetrable to weeds. If you don’t have to have the perfectly manicured garden, consider planting a nitrogen fixing plant under your trees so that the trees have a free source of nitrogen. Examples include members of the legume family such as peas and beans, alfalfa and clover.

I hope that you’ve gleaned a bit of useful information from today’s post. Take a look around your yard and other landscapes to see if you spot any of the “glyphosate cankers”. Let me know what you find by leaving me a comment below or sending me an e-mail at stacey@midatlanticgardening.com. Happy gardening!

March 13, 2012Permalink 2 Comments