Sean has been in the industry of gardening and landscaping since 2006. He is also a certified arborist that specializes in plant health.
Vinegar Weed Killer
Vinegar can be used as a relatively safe household weed killer without causing significant harm to people, animals, and the environment when used correctly. Vinegar is effective due to its ability to draw moisture out of foliage.
Household vinegar may have to be used in combination with other household items, like salt and dish detergent, to kill mature weeds. Horticultural grade vinegar has a much higher acetic acid content but should be used only if household vinegar fails to kill targeted weeds.
How Vinegar Kills Weeds
Vinegar is created via a fermentation process and the result is acetic acid. Acetic acid is a desiccant which means it draws moisture out of plant foliage. Vinegar is non-selective and will kill weeds along with any other plant it contacts. Spot treating weeds is the most useful scenario for vinegar herbicide. Some plants may be resistant due to waxy or hairy leaves, so vinegar applications are not always going to be successful.
Household vs Horticultural Vinegar
- Household Vinegar: Vinegar contains acetic acid that is toxic to plants, but the concentration of acetic acid is key to provide an effective kill. Household vinegar only contains around 5% acetic acid, which will kill seedlings, young weeds, and even mature weeds depending on how susceptible the weeds are to household vinegar. Always start with household vinegar and spray a few weeds to see how susceptible they are. Apply horticultural vinegar when there is no threat of rain in the near future. If household vinegar does not kill the weeds, then horticultural grade vinegar or a vinegar and salt/detergent combination will be necessary.
- Horticultural Grade Vinegar: Horticultural vinegar is many times stronger and more effective against stubborn, mature weeds due to having an acetic acid concentration of 20%. Apply horticultural vinegar when there is no threat of rain in the near future so the vinegar is allowed to be taken up by the plant without rain washing it off. Spray directly onto plants and do not dilute with water. Be careful when spraying to avoid non-target plants. Vinegar is indiscriminate and will kill non-target plants along with weeds. Avoid over-spraying as much as possible.
Reapplying vinegar is usually necessary, especially against weeds like crabgrass. Vinegar does not linger in the soil and prevent new weeds from sprouting. Spray new weeds immediately for maximum effectiveness. Reapplication is a slight downside to using vinegar as a chemical herbicide alternative.
Vinegar Weed Killer Combinations
- Salt and Vinegar: Mix 1½ cups of table salt into 1 gallon of household vinegar. Mix thoroughly so all the salt dissolves. Undissolved salt will settle on the bottom of the sprayer and may even plug the sprayer nozzle. Apply by spraying onto target weeds. Salt is very effective in tandem with vinegar, but salt solutions can cause damage by soaking into the soil and spreading into non-target areas and plants. Be very cautious and use sparingly when applying salt solutions since non-target plants and lawns in the direct vicinity can easily be killed. Salt remains in the soil for a while and may cause lingering problems in other plants. Salt is best used against weeds in sidewalks, patios, and other hard surfaces.
- Dish Detergent and Vinegar: Mix vinegar with a few squirts of liquid dish detergent into a sprayer or small spray bottle. Apply the mixture by spraying during the sunniest and warmest part of the day. Hot summer days provide the best results because the soap will dry into a film on foliage while helping lock in the vinegar.
Reapplying mixtures is usually necessary, especially against resilient weeds. Such mixtures do not remain active for very long which allows new weeds to emerge. Spray new weeds as soon as possible.
Treat Vinegar Weed Killer as a Chemical Herbicide
Use vinegar and vinegar mixtures like every other herbicide and pesticide. Just because it is a common household item does not mean it can be used carelessly. Injury can occur to people, pets, and the environment if used recklessly. Every weed problem has its own unique scenario and blindly spraying vinegar and vinegar mixtures is highly discouraged. Also, household vinegar should be tried before resorting to stronger horticultural vinegar. Stronger is not necessarily better.
Acetic Acid in Vinegar Can Cause Irritation
- Eye irritation or burns
- Skin irritation or allergic reaction
- Digestive tract reactions or damage
- Respiratory tract irritation
Read container labels carefully before applying horticultural grade vinegar.
Vinegar Weed Killer Poll
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Question: How often should vinegar be used on weeds?
Answer: Apply vinegar to weeds about 2-3 times to ensure the roots are killed off. Some weeds may require more applications, while others may only require one.
Question: Will the salt and vinegar solution kill moss on patio and walk bricks?
Answer: Yes, a salt and vinegar solution should kill moss on sidewalks and patios.
Question: I am getting ready to use a solution of 30% vinegar diluted down to kill some weeds, but will it kill the good grass?
Answer: The grass may be killed. It is best to use a vinegar, salt, and detergent solution to spot-treat weeds.
Question: How do you use vinegar to kill poison ivy?
Answer: Continue to soak the ivy with vinegar spray every couple of days. Poison ivy is a tough and hardy plant, so repeated applications are necessary.
Question: Will vinegar kill my regular grass?
Answer: Yes, it will kill grass. A salt and vinegar is a non-selective herbicide, meaning it will kill or damage what it is applied to.
Question: Should I heat the vinegar to kill weeds?
Answer: No. There is no need to heat up the vinegar before applying it to weeds.
Question: Will vinegar harm grape vines?
Answer: Vinegar will harm grapevines if applied directly to the plant. Using vinegar as a weed killer makes it a non-selective herbicide, and non-selective herbicides can damage any plant that it comes in contact with.
Question: Will vinegar kill poison hemlock?
Answer: Yes, but repeated applications of vinegar may be necessary to kill weeds.
Question: how can I kill weeds in a jasmine bed without killing the jasmine?
Answer: You would need to selectively spray individual weeds or remove the weeds by hand. This may become labor intensive and time consuming.
Tmilleraires@gmail.com on July 09, 2019:
what is the best to kill Japanese bamboo....it accumulates big time....
Nohr on May 31, 2019:
Put straight borax on a ant hill years ago ( that is main ingredient in ant poison)and that alone killed the grass there, took a few years to fill in again
andy on April 17, 2019:
will lemon juice help with vinegar
Eva on September 12, 2018:
How to make 20% acid vinegar at home
Tim on July 25, 2018:
I am confused. Vinegar is an acid, but isn't soap/detergent base? If you mix them, it seems you are weakening the acidic properties of the vinegar which is what is the weed killing element. I know you want it to stick to the leaves, but this seems incongruous.
Riviera Rose from South of France on March 14, 2013:
I've been meaning to start using vinegar as weedkiller for a while now, so this hub's really made me enthused. I get patches of this really invasive climbing spiky thing (no idea!) and my plan is to cut it down and then spray what's left with vinegar. Brilliant idea to put it into a washing up liquid bottle that's still got some detergent in it - thanks a lot!
rexy on February 13, 2013:
very interesting hub.... for years l just sit back and watched those weeds.. grow... and lazy to go out to buy weed killer... l am certainly going to try out your vinegar weed killer... very cool... always have the vinegar but never thought to use it this way.... great interesting hub.....
sweethearts2 from Northwest Indiana on December 28, 2012:
I haven't tried vinegar as a weed killer, but will do so in the future. Thanks for the info.
moonlake from America on December 27, 2012:
Yes I have used vinegar to kill weeds it works. Voted up on your hub.