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Using Vinegar to Kill Weeds: All You Need to Know

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Using Vinegar to Kill Weeds: The Ultimate Guide

Used for almost everything from a method for losing weight to being added to cleaning solutions for indoor use. This is because vinegar contains, to various degrees, acetic acid. This ingredient is a byproduct of the fermentation process.

It can and with varying degrees of success due, mostly, to the acetic acid it contains, be used to kill weeds permanently.

It’s certainly a great deal cheaper than commercial herbicides and safer too. Here’s everything you should know before using this method.

What kind of vinegar should be used?

There are many types of vinegar on the market, and most of them are for cooking. The one that should be used is regular white.

Apple cider can be used as well, but it costs a great deal more than white, and they both contain the same amount of acetic acid.

Both contain between 5-8% acetic acid depending on the manufacturer. The label will tell you exactly how much.

What if acetic acid alone isn’t working and why?

If undiluted white type alone isn’t working, you can add either Epsom salt or organic castile soap.

Epsom salt helps the acid in the vinegar dry out the weeds.

For the recipe, you add anywhere from ½ to 2 cups of Epsom salt to one gallon of vinegar. It all depends on how long you want to keep something from growing in that spot.

Castile soap is a surfactant which removes oil, and it’s this feature that allows it to cut through the protective oils a lot of weeds are coated with, allowing the acid to dry them out.

The consensus is 1-2 teaspoons of liquid soap to one quart of vinegar. Overuse is just a waste.

Why use horticultural grade rather than white vinegar?

A horticultural vinegar should be used on mature weeds that are resistant to white. It has 20-30% acetic acid depending on the manufacturer.

Soil Mender is also another option. It contains 10% acetic acid along with other natural ingredients which makes it highly effective as an organic contact weed killer.

How do you apply it?

Typically, a sprayer is used to apply the solution.

A pump sprayer with a long nozzle and hose is recommended for large areas while either a hand sprayer or paintbrush can be used for small areas.

Paintbrushes are ideal for single weeds surrounded by good grass since you just paint it on. This will keep you from killing the grass on accident.

You can also use hot vinegar in a sprayer if trying to achieve more permanent results. 

How many times should you apply it?

This depends on how resistant they are to it. In the beginning, the solution is applied and then, it’s checked 8 hours later. If a second application is needed, it’s done and checked 24 hours later.

It usually takes about 24 hours for good results. Resistant weeds will need multiple applications over the course of a few days before their roots die.

Afterward, apply every two weeks as recommended by the experts.

How long does vinegar last in soil?

It only stays in the soil until it either rains heavily, or there’s a saturation of irrigation water. These will dilute it and wash it out of the soil.

When should it be used?

For removing annuals like crabgrass, it should be done before the weed goes to seed to prevent it from propagating. Success is also easier achieved with shoots and young plants rather than an older, mature one.

For perennials, removing the flower heads is a must to prevent seeding. They must also have the solution applied directly to their roots for fast results.

For both, the application should be made when it’s sunny and hot, around 70 degrees or higher and when there is no rain in the forecast for several days in a row.

How safe is it?

Due to its acidic nature, it should be treated as a chemical herbicide.

Yes, it’s a natural one, but it can still hurt, even injure, if not handled properly. It can hurt not just the plants you want to keep, it can also hurt people and animals in the following ways:

  • Eye irritation and burns
  • Skin irritation
  • Allergic reaction
  • Digestive tract reaction or damage
  • Respiratory irritation

What precautions should be taken when using vinegar?

To avoid any possible health issues related to using this weed control method, especially the horticultural grade, you should wear gloves.

This is especially necessary when mixing it with either Epsom salt and castile soap. Eye goggles are recommended as well.

Using a sprayer or paintbrush can result in back spray and splashes to the face.

How effective is vinegar as a weed killer?

It’s definitely more cost-effective than pulling by hand.

If it’s used properly at the right time, in the right amount, and for the required amount of time, it’s incredibly effective at removing, and maintaining control.

Please note, it is non-selective — it will kill whatever plant life it touches. This can include plants you want to keep so be mindful of application.

Is using it cost-effective?

Because vinegar is so cheap, it is more cost-effective and safer than chemicals. It doesn’t take a lot to cover a large area. In fact, it only takes one gallon to cover a large patch.

Even with Epsom salt or liquid soap added, it’s still cheaper than commercial alternatives. The only thing cheaper is hand pulling it yourself. It’s even cheaper than paying someone to pull weeds for you.

Vinegar is one very useful and natural weed killer. It adds yet another tool to the gardener’s arsenal.

By using the right amount at the right time, this product can be a very effective method of getting rid of weeds in your vegetable garden, on the lawn and patios, pavers, walkways, and the driveway.

Sasha Brown

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