Yes, vinegar can be used effectively in the garden to kill weeds but there are things you need to know so that you don’t kill everything and ruin your soil. White vinegar works as a fungicide, a poison, a source of nutrients, and for cleaning tools and pots. Be sure to read my entire post here because there are two studies, cautions and dilution ratio’s to follow for best results and so you don’t ruin your soil (vinegar can change your soil pH) and any beloved plants. I will also cover 17 other ways you can use vinegar in the garden.
A little about vinegar: Vinegar results when just about anything with sugar is fermented to form alcohol and then is fermented again. Commercial manufacture was common by 2000 b.c. Making it at home has concerns because usually it will not reach strengths of more than 3 percent, making it unsuitable for canning and pickling (which needs an acidity level of at least 4%).
A Note on Acetic Acid: It is NOT Vinegar
The United States Food & Drug Administration (FDA) recognizes that diluted acetic acid is not vinegar, indicating that it is:
“…misleading if the labeling of a food in which acetic acid is used implies or suggests that the food contains or was not prepared with vinegar. Acetic acid should not be substituted for vinegar in pickled foods, which consumers customarily expect to be prepared with vinegar.”
5 Cautions About Using Vinegar
- Using vinegar in the garden will kill any type of plant or tree if incorrect dilutions are used, thus… read carefully and take good notes!
- Vinegar strips the waxy protective coating from the plant surfaces, causing the leaves to dry out and often desiccating the plant all the way down to the roots. In cooler climates such as the Pacific Northwest, vinegar doesn’t work nearly as well.
- Avoid vinegar treatments altogether on windy days. If you need to spray near other plants in the garden, protect them with a piece of plastic or cardboard as you spray the weeds.
- Never use the garden-variety (20 percent acetic acid) vinegar for cooking or gardening.
- Although vinegar and citrus herbicides contain all-natural ingredients, that doesn’t mean that they don’t pose a threat to humans and other critters. “Try to avoid using them when the bees are buzzing and other beneficial bugs are active, and avoid using them near ponds that contain fish, or near edible food crops,” says Master Gardener and HDTV host Gardening by the Yard, Paul James.
Before Killing Any Plant in Your Garden Consider if it is Free Nutritious Food
Herbicides made from various citrus oils and from oils of clove bud and cinnamon bark work every bit as well as concentrated vinegar, and they smell a whole lot better, too.
Citrus-based herbicides are similar to vinegar herbicides in that they are also non-selective when it comes to plants.
Two Studies on Killing Weeds with Vinegar
Note, it is recommended that vinegar be used as a “spot treatment” in the garden, never broadcast. Using a 5 percent dilution on young weeds. Its effectiveness can be increased with repeat applications, by heating the vinegar, or by soaking the weeds with your vinegar mixture in full sun.
Caution: Vinegar is non-selective and will kill a weed as quickly and easily as your prized plant!
VINEGAR AS A NON-TOXIC AND SAFER WEED CONTROL OPTION
Authors: Radhakrishnan, Jayakumar, Teasdale, John, Coffman, Charles
Submitted to: BARC Poster Day Publication Type: Abstract Publication Acceptance Date: April 18, 2002 Publication Date: April 18, 2002 Citation: RADHAKRISHNAN, J., TEASDALE, J.R., COFFMAN, C.B. VINEGAR AS A NON-TOXIC AND SAFER WEED CONTROL OPTION. BARC POSTER DAY. 2002.
Technical Abstract: Vinegar (acetic acid) is registered as a herbicide for weed control in concrete pavements in Sweden (David Hansson, personal communication). However, there is no scientific literature on the use of vinegar for agricultural purposes available. The objective of this research was to study the efficacy of vinegar as a potential candidate for weed control in organic farming situations. Replicated greenhouse experiments were conducted during Spring and Fall 2001. Common lambsquarters, giant foxtail, and smooth pigweed and Canada thistle were sown in pots and irrigated regularly. The plants were hand-sprayed with 0.0, 5.0, 10.5, 15.3 and 20.2 percent vinegar to obtain a uniform wetting of all foliage. The results indicated that the effectiveness of the vinegar to kill weeds was dependent on the concentration and the plant growth stage. Lower concentrations of 5 and 10 percent were more effective in killing the weeds during the early stages while at later stages they were not as effective as the 15 and 20 percent concentrations. Vinegar provided 95-100 per cent kill at all growth stages of the weeds studied at 15 and 20 % concentrations. Canada thistle was the most susceptible species with 100 percent kill of top growth with 5 % vinegar. Vinegar has a potential to be used as an inexpensive, herbicide for spot treatment of organic farms.
AGRICULTURAL APPLICATIONS OF VINEGAR
Authors: Radhakrishnan, Jayakumar, Teasdale, John, Coffman, Charles
Submitted to: Proceedings of Northeastern Weed Science Society Publication Type: Abstract Publication Acceptance Date: January 6, 2003 Publication Date: January 16, 2003 Citation: RADHAKRISHNAN, J., TEASDALE, J.R., COFFMAN, C.B. AGRICULTURAL APPLICATIONS OF VINEGAR. PROCEEDINGS OF NORTHEASTERN WEED SCIENCE SOCIETY. 2003.
Technical Abstract: The objectives of these studies were to evaluate 1) the efficacy of vinegar to control weeds when used as a directed spray at the base of crops, 2) rates and volume of vinegar required to achieve weed control when broadcast, and 3) soil drench as a method of control for Canada thistle. The injury to corn in the first experiment ranged from 5-35%. The replicated experiments suggested that the foliar application damaged corn more than the basal spray and the 20 % application was more injurious to corn than the 10% application. The corn grain yields did not show significant differences for all treatments from the weed free controls but the coefficient of variability was very high at 55% due to extreme droughty conditions. The crop injury in soybeans ranged from 5 to 45%, with the younger plants showing more injury than older plants. The soybean yields did not show significant differences among the weed free controls and the vinegar treatments. In all the trials weed control ranged from 90 to100 percent. An investigation of the effect of vinegar soil drench in an established Canada thistle patch was conducted on an Elkton silt loam soil. The results showed 90% reduction in the number of stems and plant biomass in all vinegar treatments compared to the control. The pH of the soils ranged from 5.9 to 6.6 at the beginning of the experiment in October 2001 and declined to 4.7 to 5.2 in the vinegar treated plots a month later. However, the pH in the treated plots ranged from 5.8 to 7.1 by April of the following year.
Clearly, dose is the secret to whether vinegar used in the garden is a remedy or an herbicide.
17 Other Ways of Using Vinegar Around the Garden
- Cleaning Garden Pots: The same principle as using vinegar to clean coffee pots is true for cleaning garden utensils. Wiping pots with vinegar removes lime and hard water deposits. For persistent stains soak them in full-strength (5 percent) vinegar and rinse well.
- Cleaning Garden Tools to Prevent Spreading Disease: To reduce disease through garden tool use soak tools in full strength vinegar whenever necessary or at the end of the season. Wiping them with vinegar helps, soaking for 20 minutes or longer is better if you suspect a plant infection.
- Ant Deterrent: Ant invasions can sometimes be deterred by washing counter tops, cabinets and floors with white distilled vinegar. Try making a spray, use it around doors and windows.
- Get Rid of Fruit Flies/Gnats in Your Kitchen: Place a bowl filled with ½ quart water, 2 Tbsp. sugar, 2 Tbsp. apple cider vinegar and a couple of drops of dish soap to attract the fruit flies. Always eliminate the source of attraction, i.e., ripened produce.
- Powdery Mildew: diluted vinegar works to control the spread and not damage the plants… keyword here is ‘diluted!’ My personal preference for dealing with Powdery Mildew (because it feels safer) is to use the light dilution ratio of the Thieves Household Cleaner and spray upper and underside of leaves every 2-3 days for 1 – 1 1/2 weeks, I’ve found it to work like a charm and not risk killing my plants.
- Acid-loving Plants: use one cup of vinegar to every gallon of water once a month. Do NOT do this if your soil is acidic, instead… top-dress with powdered garden Lime!
- Vinegar for Slugs: very lightly spray the ground around the base of the affected plants/bushes with diluted vinegar. You will need to reapply this after every rain but the dose is so light that it shouldn’t change soil acidity.
- Keep Flowers Longer: Keep cut flowers fresh longer. Add 2 tablespoons sugar and 2 tablespoons white vinegar in a 1-quart vase of water. Trim stems and change water every five days.
- Plant Nutrients: Mix vinegar and water in a ratio of 1:8 (1 part vinegar to 8 parts water). Mix a separate solution of sugar and water in a mixture of 1:8. Combine the vinegar and sugar mixtures. Add to plant as long as needed.
- Stop Itching: Apply a paste made from vinegar and cornstarch. Keep on until itch disappears.
- Neutralize Garden Lime on Hands: Rinse your hands liberally with white distilled vinegar after working with garden lime to avoid rough and flaking skin. Clean pots before re-potting, rinse with vinegar to remove excess lime.
- Cleaning Heavily Soiled Hands: Moisten cornmeal with apple cider vinegar. Scrub hands, rinse in cold water and pat dry.
- Get Flies Away From Your Pool: Pour vinegar around the sides of your pool to help keep flies away. Caution: doing this too much or too often WILL change the soil pH and/or kill plants in your landscape, so you may just want to pour vinegar in some bowls and place them in good locations around the pool.
- Vinegar as a Mosquito Repellent: Drink a couple of spoonfuls of Bragg’s a day to keep mosquitoes away from you – your perspiration will be unpleasant. I recommend using “Braggs” as it is designed for internal use.
- Remove Berry Stains From Hands: Pour a little vinegar on your hands before washing and the stains should come off much easier.
- Vinegar for Fleas and Ticks: I have not tried this yet, but WILL… add a teaspoon of white distilled vinegar for each quart bowl of drinking water helps keep your pet free of fleas and ticks. The ratio of one teaspoon to one quart is for a forty-pound animal. I have also read that vinegar can be used as a spray on dogs to repel insects, however… doing this too often can be harsh on your dog’s skin, therefore I am not likely to try this method. I have used Bragg’s Apple Cider Vinegar as a diluted spray (1/8 cup vinegar to 14oz. water) to deter fleas on my dog, it works fairly well enough if applications are maintained daily. I did not find it to do anything in regards to ticks, for ticks the best we’ve found is Palo Santo essential oil. Read about our tick and essential oil experiment.
- Cure Lawn Brown Spots From Dogs: Put a teaspoon of vinegar for each quart bowl of drinking water in your dog’s drinking water every day and you will no longer have those brown spots in your lawn from the dog’s urine.
1. Vinegar Institute
2. Back Home Magazine, Vinegar in the Garden
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