Vinegar is Now the Active Ingredient in Roundup

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Robert Pavlis

Roundup is a household name in gardening and farming communities. Initially known for its glyphosate-based formula, it has evolved into a product line with various formulations. This article provides an overview of different Roundup products, with a focus on the new vinegar-based Roundup and its possible use in organic gardening.

Several different types of roundup beside each other

Roundup Products

Traditionally, Roundup contained glyphosate, a broad-spectrum herbicide that many have come to detest. Glyphosate was celebrated for its effectiveness in weed control, but over time, concerns about its environmental and health impacts have cast a shadow over its widespread use. Critics of glyphosate argue that its residues remain in the soil and ecosystem, potentially causing harm to non-target organisms and contributing to biodiversity loss. In actual fact the half-life in soil is quite short.

In response to growing concerns and regulatory actions against glyphosate, Bayer (formerly Monsanto) has developed newer Roundup products that contain alternative formulations. These new products come with a variety of active ingredients intended to provide options for consumers who are wary of glyphosate. Product availability varies by country.

Roundup With Vinegar (Acetic Acid)

One of the most notable new Roundup formulations is based on vinegar. Unlike traditional glyphosate products, this formulation contains no glyphosate or other synthetic herbicides. This development raises an interesting question: can Roundup with acetic acid be used in organic farming?

Plant Science for Gardeners by Robert Pavlis

Certified Organic Farming and Acetic Acid

Acetic acid is approved for use in certified organic farming, but the rules governing its approval are nuanced. The key distinction lies in the source of the acetic acid. If it is derived from petrochemicals, it is not permitted in organic farming. However, if the acetic acid originates from a fermentation process, it is allowed. Curiously, both methods produce the exact same chemical, acetic acid, raising questions about the rationale behind this differentiation. Despite this, Roundup with acetic acid is not approved for organic farming, likely due to the fact that it is petrochemical-derived.

Should You Buy This Product?

This product contains 6.25% acetic acid. Compare that with most household vinegars at 5% and picking vinegar at 7%, both of which are much cheaper. For this reason I would not buy vinegar-based Roundup.

How Effective is Vinegar for Weed Control?

Household Vinegar

Household vinegar typically contains 3-5% acetic acid. While it may seem like a natural alternative for weed control, its effectiveness is limited. It can kill very small seedlings, usually no older than two weeks, by blackening their leaves. This “burning” effect occurs because acetic acid acts as a contact herbicide, affecting only the leaves and not the roots or crown. Consequently, plants treated in this way often regrow from their unaffected roots, rendering this method almost useless for effective weed control.

Higher Concentration Acetic Acid

Commercial products containing at least 20% acetic acid, offer more effective weed control. This higher concentration can kill some annual weeds and sufficiently damage certain perennial weeds to kill them. However, it is not effective on all weeds.

Chemically, the acetic acid in both household vinegar and commercial products is identical. Therefore, for serious weed control, opting for a product with 20% acetic acid is advisable for better results.

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Toxicity: Glyphosate vs Vinegar

Many people assume that vinegar is inherently safer than glyphosate, but toxicity data paints a different picture. The LD50 value is a measure of toxicity.

  • Glyphosate LD50 (rats): Approximately 5600 mg/kg.
  • Vinegar LD50 (rats): Approximately 3300 mg/kg.

A higher value indicates that more of the chemical is required to kill the subject animal. Vinegar is twice as toxic as glyphosate when considering these metrics. Despite vinegar’s higher toxicity, both substances are extremely safe when used appropriately.

Moreover, the widely held belief that glyphosate causes cancer has been debunked by multiple regulatory bodies and scientific assessments. Over 20 organizations, including the EPA and international regulatory bodies in Europe and Canada, have stated that glyphosate does not cause cancer. Even some court cases that originally concluded glyphosate caused cancer have been reversed.

Glyphosate can be found in many places including drinking water, mothers milk and soil. That scares people but that fear is unfounded when you look at the extremely low levels found. For a better understanding of this, have a look at Unnatural Fear of Roundup – Understanding Small Numbers

Other Roundup Products

Monsanto (now owned by Bayer) has leveraged the well-known Roundup brand to introduce a variety of products targeting different markets, particularly in regions where glyphosate has faced regulatory bans. For instance, countries like Canada and some in Europe have banned the sale of glyphosate-based herbicides to the general public, although farmers may still use them.

Traditional Roundup contains glyphosate and is sold in bottles with purple caps. Some examples of new roundup formulations include the following.


Roundup Concentrate Plus:

This product contains glyphosate and diquat, a chemical ten times more toxic than glyphosate. It is packaged in white bottles with red caps.


Roundup Ready to Use Plus:

This formulation combines glyphosate with pelargonic acid, a relatively safe chemical. It comes in white bottles with blue caps.


Roundup Extended Control:

It contains a blend of pelargonic acid, diquat, and Imazapic, offering extended weed control. It is available in gray bottles.


Roundup Advanced:

This version contains acetic acid (6.25%) and is sold in white bottles with orange caps. It also contains a small amount of citric acid.


Roundup Advance:

This product, which also contains glyphosate, is packaged in green bottles with a yellow cap. It is sold in Australia.

Key Takeaways

Specifying Roundup Products

Given the diversity of Roundup formulations now available, discussing “Roundup” without specifying the exact product and active ingredient is increasingly meaningless. Conversations about the effectiveness, safety, or ethical considerations of Roundup must include these crucial details to be productive.

Importance of Reading Labels

Consumers need to be diligent about reading labels when purchasing Roundup products. Each formulation has different active ingredients suited for various applications and regulatory environments. Without this careful scrutiny, gardeners risk choosing a product that may not address their needs effectively.

In conclusion, Roundup has evolved significantly from its original glyphosate-based formulation, now encompassing a variety of products to meet diverse consumer needs and regulatory requirements. Understanding these differences, the nuances of organic farming regulations, and the true toxicity profiles of these chemicals is crucial for informed and responsible gardening practices.

Frequently Asked Questions About Using Roundup

The answers to these questions will depend on the version of Roundup you are using. The following applies to the traditional product containing glyphosate.

What is Roundup, and how does it work?

Roundup is a herbicide used to kill weeds. The ingredient glyphosate enters the plant through its leaves and stops a specific enzyme that is only found in plants, disrupting the plant’s growth and eventually killing it. Acetic acid is a contact herbicide that disrupts the surface of the leaf.

Is Roundup safe to use in my garden around pets and children?

Glyphosate is safe if used correctly. Keep pets and children away from treated areas until the product dries completely. Once it’s dry, it’s safe for them to return.

How long does it take for Roundup to kill weeds in my garden?

Glyphosate takes 7 to 10 days before you see the effect. Weeds are usually dead after 10 days. Some of the newer formulations include a second herbicide that burns down the leaves quickly and then glyphosate works slowly to kill the root.

Can Roundup harm other plants in my garden besides weeds?

Roundup is non-selective and can harm any plant it touches. Apply it carefully and avoid using it on windy days to prevent it from drifting onto other plants. One of the best ways to apply it in a garden is to use a paintbrush to apply it only to the weed.

How often should I apply Roundup in my garden to keep weeds under control?

Apply Roundup only for difficult to control weeds and only when needed. Follow the instructions on the label for the best results.

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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

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