DIY Vinegar Weed Killer Guide

As gardeners, we regularly battle weeds. Throughout the year, we are constantly faced with weed problems in our gardens, both annual and perennial. Our lawns and gardens are particularly prone to weeds sprouting and reseeding. We strive to make sure they are removed as quickly as possible. 

Your body should not be exposed to harmful chemicals from the garden if you eat the veggies out of it. An alturnative method is to use Vinegar as a homemade weed killer.

Vinegar as a weed killer

How vinegar as a weed work? 

On contact with acetic acid, also known as vinegar or ethanoic acid, the leaf tissue of the plant rapidly breaks down and becomes desiccated.

It causes the water to be drawn out of the weed, whilst the washing up liquid allows the vinegar to stick onto the plant for a longer period of time giving it the best chance to break down the outer coating.

What strength of Vinegar to use?

Normal household vinegar is 5% acetic acid, however you can purchase vinegar that has 10%, 20% or even a higher percentage of acetic acid.

 20% and above acetic acid vinegar is considered an industrial herbicide and can cause chemical burns and even blindness if it gets into your eyes. 

How to make DIY Vinegar Weed Killer?

The easy way:

Making your own vinegar weed killer is as easy as mixing washing up liquid with standard 5% vinegar in a spray bottle and then spraying it. 

You should note that this solution works best on new weeds with only 2 or 3 leaves on, and you should see signs within 24hrs of application.

Whilst vinegar is the main ingredient it will work better when combined with other ingredients.

The harder way, a more potent version:

  • 10% Vinegar – 2 Litres
  • 5 Tablespoons of salt
  • Half a tablespoons of washing up liquid 

Mix all the ingredients together into a sprayer and apply.

An even harder version which is even more potent than the previous two:

  • 20% Vinegar – 2 Litres
  • 500ml (half a litre) of water
  • 5 Tablespoons of salt
  • Half a tablespoon of washing up liquid

Again mix all the ingredients together into a sprayer and apply.

With this mixture the added water creates a larger quantity of solution even though it will dilute the vinegar. However in this case it’s not an issue as your using 20% Vinegar

How to apply your DIY Vinegar weed killer

Listed below are some guidelines you should follow before applying this weed killer:

  • In addition to damaging/killing undesirable plants, vinegar or soap is non-selective. Apply weed killer with caution.
  • Ensure that the application is done on a sunny, windless day. Sunlight dries out the weeds. In order to prevent inadvertent spraying onto other plants, you’ll also want to wait for a windless day.
  • It is possible that the root of the weed is not killed by the vinegar weed killer. The weed killer may need to be reapplied if green growth appears afterward or poured over the root zone in order to kill large persistent weeds effectively.
  • There are some types of weeds that a 5% vinegar weed killer won’t kill, so test it out in your own garden to determine if it works.

Acetic Acid has been used as a natural weed killer by organic farmers for several years now according to a report published by the Cambridge University Press.

Vinegar test before
20% Vinegar test area before
Vinegar test after
20% Vinegar test area 24hrs after

Vinegar: Is it an organic control?

Well yes and no, it depends on how the vinegar you are using is made. Vinegar can be made from multiple sources, you can make it from wine, rice, wheat, potato and the list goes on. Then it is considered organic. In contrast, synthetic acetic acid is not.

Vinegar’s Effect on Soil

It can lower the soil’s pH slightly since it’s acidic. The effect will only last for a short time. After the first watering or rain, any residue from acetic acid will be pretty much gone.

The use of household vinegar as a weed control solution is not a long-term solution that is ideal for gardeners. It should not be applied on lawns or around ornamental plants however it’s great for paths and drives. 5% Vinegar purchased from your local supermarket should not be used as long term control as it will not be strong enough. Preventative methods as well as pre-emergent solutions are the best ways to control weeds. Getting rid of weeds begins with stopping them before they start.

If you would prefer to use commercially available weed killers we have reviewed the best weed killers available on the UK market.