Kill Weeds With Vinegar, But This Comes With A Warning!


One of the reasons I find vinegar herbicide especially favorable is because it uses all-natural ingredients. Additionally, in minor cases with young weeds, everything you need to make your mixture are household supplies that you probably have lying around.

Vinegar can work as a powerful weed killer for any organic garden. Acetic acid is the active ingredient in vinegar that eliminates weeds; the greater the concentration of acetic acid, the more effective it will be—exercise caution when using vinegar in your garden. Vinegar is a nonselective herbicide known to harm the surrounding plants, so take this into mind.

In this post, I will outline how to best use vinegar safely and effectively to rid your garden of weeds.

Vinegar percentage needed when using it to kill weeds.

From my experience, if you are serious about ridding your garden of weeds, you will require vinegar with a 20 to 30 percent concentration of acetic acid.

Household vinegar has about 5 percent acetic acid and will not be good to use as a weed killer; instead, use horticultural grade vinegar which you can find at the garden and home improvement stores.

Studies have been done about the usage of 5-10 percent vinegar concentrations and were said to have been effective within 2 weeks of application. Higher concentrations of vinegar for older plants must be applied to kill weeds (source) effectively.

When applying horticultural vinegar, prevent it from touching your skin, and never touch your face. Wear eye protection, and cover your skin. If using a spray bottle, always spray downwards away from your body, in the same direction as any wind.

When to Use Vinegar to kill weeds

Observe your garden the year before applying. Keep track of when weeds start to grow and consider the types of weeds you are trying to control before you choose to use vinegar. Keep in mind the old saying: “Know your enemy!”

Annual Weeds and when to use vinegar to kill these weeds

One must strike during seeding before annual weeds sprout a new generation. Depending on the species, annual weeds may seed in the spring or the summer. One timely application of vinegar will likely be sufficient to eliminate any annual weeds.

Perennial Weeds, what to do to eliminate them while also using vinegar to kill the weeds

Controlling perennial weeds is not as simple and may rely on you taking action throughout the season to prevent future growth. For example, dandelions spread like wildfire due to their clever seeding adaptations. I like to use a dandelion rake to snap off their flowers whenever I see them.

If weeds constantly overrun your garden rows, ask yourself what those are and why they are growing there. Put down the hoe long enough to consider what the weeds are telling you.

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If you keep this up throughout the season, it will prevent them from multiplying, but it won’t stop them from reoccurring in the next season.

When winter is approaching, dandelions and most perennials live on through their roots. One must repeatedly apply vinegar to the plants throughout the season to slowly weaken the weeds until a final death occurs before winter.

Drawbacks and Weaknesses on using Vinegar to kill weeds

Vinegar is an effective herbicide in areas where grass or other plants are not in the way, such as in a rock garden, patios, or walkways where isolated weeds grow through the cracks.

However, it is highly discouraged to kill weeds in lawn areas using vinegar, as it could kill the grass around the weeds and make your lawn patchy.

Non-natural herbicides are typically effective with fewer uses, composed of compounds that absorb deep into the weed, reaching the root and killing the weed. Vinegar mostly does topical damage to the weed and will require a regular application to kill the plant.

How to Apply Vinegar as herbicide to kill weeds

Vinegar must be applied on a dry day and must saturate the weed. To ensure the vinegar is absorbed by the weeds, prepare a mixture of water, dish detergent, and vinegar.

You will need to take safety precautions and wear adequate protection. Below, I will give step-by-step instructions on the methods I use.

What you will need to make a vinegar solution to kill weeds

The materials needed can mostly be found at home, save for the specific vinegar needed for the herbicide application.

Equipment neededMaterials needed
Safety googlesWater
Waterproof glovesSalt
CoverallsHorticultural vinegar (20%-30%)
Protective maskLiquid dish detergent
Brush and spray bottle

The step by step instructions for the application of vinegar are as follows:

Ensure dryness in the area before applying vinegar to kill weeds

You will need at least three consecutive sunny days before you apply the vinegar mixture.

However, if the ground is still moist despite consecutive dry days, apply a small quantity of salt on the earth close to the weed’s base. The salt will dry out the area and encourage the absorption of the vinegar.

Please wait for the ground to be dry and the weed to be thirsty to ensure that the vinegar diffuses into the weed; this ensures that it will be a more effective herbicide.

Rain washes the vinegar off of the weed’s foliage and reduces its absorption. The vinegar has the most significant impact in the days following the application when the sun is shining.

Safety First must be ensured when making the vinegar solution to kill the weeds

When handling horticultural vinegar, you must be wearing gloves, eye protection, a facemask, and secure clothing, as mentioned in the equipment needed for applying vinegar herbicide.

Do everything you can to avoid the vinegar making contact with your skin or your eyes. You cannot ingest horticultural vinegar as you can with household vinegar.

Swallowing horticultural vinegar can cause sore throat, vomiting, diarrhea, or even death. The higher concentration of acetic acid in these kinds of vinegar can cause skin burns, severe eye damage, and cause damage to the lining of the nose, throat, and lungs if inhaled.

Contact with horticultural vinegarWhat to do to remedy these
Skin coming into direct contactImmediately flush skin with as much water as possible
Ingesting horticultural vinegar by mistakeDrink large quantities of milk or water as you can
Inhaling horticultural vinegarIf you happen to have trouble breathing, call an ambulance

Be sure to call the ambulance for serious contact with this solution instead of waiting it out and trying to remedy it at home.

Mix your Vinegar solution Herbicide to kill the weeds

The mixture and concentration of the herbicide depend on the severity of your weed problem and the size of your garden. Take into mind also only using organic vinegar and detergent without bleach and phosphates in these steps to avoid killing helpful organisms in your garden.

For the mixing ratio of using vinegar as a weed killer, use four parts vinegar to one part water.

The severity of the weed problem
or Size of garden
Plan of action
Few small weeds onlyUse household vinegar and a drop of liquid dish detergent.
For smaller sized gardensMake about a liter or two vinegar-water solution.
For larger sized gardensA gallon of solution. For each gallon of solution, add one tablespoon liquid dish detergent.

Make sure to mix your solutions well before putting them into their containers and getting ready to apply your vinegar herbicide.

Apply your Vinegar solution Herbicide to kill the weeds

Spray or brush the vinegar onto any weeds you intend on killing. If the weeds are near desirable plants, I would recommend you use a brush apply your herbicide.

Brush application will ensure you avoid getting any on neighboring plants with the spray bottle. While using a spray bottle, put the nozzle within an inch or two of the weed when spraying.

Never apply horticultural vinegar on a windy day. The vinegar could make unintended contact with other plants or blow towards you and present a safety hazard.

Effects of using dish detergent with your vinegar solution herbicide

Dish detergent acts as a surfactant that makes the vinegar more effective by counteracting a waxy coating that many weeds have on their foliage to protect themselves from the elements and insects.

For a herbicide like vinegar to yield good results, it must maintain contact with the weed’s leaves and steam long enough to absorb fully.

Consider reapplying your Vinegar solution herbicide for maximum effectivity in killing the weeds

In most cases, I have had to reapply vinegar to kill most weeds, particularly perennials. Vinegar works best on younger weeds and annual weeds like chickweed or crabgrass. Many herbicides, including natural ones, require reapplication.

Once you have completed a weed control treatment with vinegar, you will need to stay vigilant. Look out for new growth from existing roots like the taproots of dandelions and the bulbs of clovers and nut grasses.

When to reapply the vinegar herbicide to kill the weeds

As the summer progresses, continue to apply your herbicide. If weed growth has slowed down, reduce the mixture to 1 part vinegar and 1 part water, add a teaspoon or so of dish soap, and apply the said solution. If weed growth has not changed, add a half cup of salt per gallon of mixture.

Just when and at what stage of weed growth is it best to apply the vinegar herbicide solution

For your treatment to be successful, you will need to reapply your mixture to any young sprouts as soon as they appear. Repeatedly killing off the tops will starve out the roots eventually, killing off the rest of the plant. It is important to reapply your vinegar herbicide before the weeds have a chance to flower and seed.

The ideal time to apply your vinegar treatment to weeds is when they are young and small.

I tend to bring a spray bottle of my vinegar herbicide with me as I do my regular gardening and apply it to any weeds I encounter while I water other plants.

Residual effect after the application of the vinegar herbicide solution in killing the weeds

Once your vinegar mixture dries, it has no residual effect meaning it will not continue to kill plants. Provided you wait till your mixture dries on the weed, it is safe to use near areas where you are planting seeds.

The lack of residual effect of using vinegar herbicide also means the dead weeds and clippings from vinegar-treated areas are safe to feed animals.

One can also use the clippings to make compost for nourishing other plants, unlike those treated with chemical weed killers like MSMA.

Considerations when using vinegar as herbicide and its effect on soil pH

While killing weeds with vinegar is a viable organic resolution to your weed problems, you may not want to use it season after season.

It is best to avoid introducing any herbicidal products to your garden because they can have unintended effects on your garden’s ecosystem. In the case of vinegar, its acidity can impact how certain plants grow, and it could kill good microbes in your soil.

How to fix the soil pH from using vinegar to kill weeds

If you find that plants aren’t growing where you had previously used vinegar to deal with weeds, you may need to adjust your soil pH.

Since vinegar is quite acidic, repeated use of vinegar to eliminate weeds may result in acidic soil.

Although some plants prefer acidic soil, blueberries are comfortable in a pH of 5-5.5, most plants like very slightly acidic soil (a pH of 5.8-6.5). If you need to increase the pH due to excessive acidity, add some wood ashes, or pulverized lime into your soil.

Conclusion on killing weeds with vinegar

While using vinegar herbicide is effective, you must keep in mind that it shouldn’t be your only solution for managing your weeds year after year.

The best way to control your weeds is a holistic approach combining manual removal and organic herbicide.

With a wedding rake, a dandelion rake, vinegar herbicide, and a little bit of elbow grease, you will be on your way to a weed-free healthy garden. Furthermore, caring for your plants using mulch, rocks, and ground cover will keep your garden healthy and naturally have fewer weeds.

Hopefully, this article’s benefits, dangers, and limitations will help you decide to use vinegar as a weed killer. If it did and you would like to read more articles on gardening, be sure to subscribe in the form below to be notified about future content and releases!

Tony O'Neill

I am Tony O'Neill, A full-time firefighter, and professional gardener. I have spent most of my life gardening. From the age of 7 until the present day at 46. My goal is to use my love and knowledge of gardening to support you and to simplify the gardening process so you are more productive

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