There’s a lot to be said for pulling weeds by hand, but if you have stubborn weeds, you’ll want a reliable weed killer spray. But let’s face it, commercial herbicides come with some drawbacks and safety concerns (especially if you have kids and/or pets). They can also be fairly expensive, especially if you need to use them regularly. Add to this that safe disposal of excess can be a pain, and it’s no wonder you’re looking for a DIY solution. No sweat – I’ve got you. Today I’ll share my homemade weed killer recipe with you.
You can make your own weed killer that is just as effective as many store bought ones, as long as you use it the right way (I’ll tell you how).
Let’s talk about the ingredients you need and the perfect ratio for an effective homemade weed killer.
Ingredients You’ll Need to Make Homemade Weed Killer
Most homemade weed killer recipes use products you’ve already got in your kitchen cabinets. Stuff you can actually pronounce, and would be comfortable keeping in your house without fear of them killing you.
The most popular ingredients include salt, dish soap, and white vinegar.
You can either spray your mixture directly onto the weeds or pour it into the soil below the weeds and, well, they’ll die.
But there are additional ingredients you can add to make it stronger.
Here is a step by step guide to how to make homemade weed killer. I’ll also include a few tips on how to apply it, as well as other types of herbicide options.
Steps To Make A Homemade Weed Killer
Here are the things you need to make a homemade weed killer.
- White Vinegar
- Dish Soap
- Spray bottle (optional)
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You will have to mix different amounts of each ingredient depending on how much weed killer you want and how powerful you want it to be, but here’s the basic ratio you should work from:
My go-to recipe for homemade weed killer is to mix the following ingredients together in a large container:
- One gallon of white vinegar
- One cup of salt
- One tablespoon of dish soap
But let’s be real – you might not need to mix up a gallon of homemade weed killer in a single session. And you probably don’t have a gallon of white vinegar sitting around (maybe you do, but in my experience most people don’t).
A Better Recipe (for most people)
So here’s a mixing ratio that’s more accessible (it’s a little heavy on the dish soap, but I find that sticks to the 1/4 teaspoon measuring scoop anyway so it comes out just about perfect):
- 1 Cup of White Vinegar
- 1 Tablespoon of Salt
- 1/4 Teaspoon of Dish Soap
That recipe should be in quantities that are easy to measure with your standard kitchen measuring cups, and it’s easier to scale up for those of us who are math-challenged if you find you need a little more.
How to Use it To Kill Weeds
A spray bottle works well to apply this, and if you mix a larger quantity you may want to invest in a pump sprayer for $18 or so at the local hardware store.
But you don’t really need either of them. If you have a limited number of weed patches, you can think about pouring this mixture directly into the soil right from your Pyrex measuring cup. This method lets you skip the spray bottle altogether.
Be cautious, though. I only recommend this method when the weed patch is large, or if your garden has been completely overtaken by an invasive weed species.
An Important Warning
This weed killer is non-selective – it’ll kill your grass and/or perennials just the same way it will kill your weeds.
While white vinegar, dish soap, and salt are the three required ingredients, you can also add other ingredients to your homemade weed killer.
Some Optional Additions & Substitutions to This Recipe
For example, corn gluten can help stop weed seeds from germinating and growing.
It’s a by-product of milling corn and serves as a natural pre-emergent herbicide, killing weeds at the root before they even have a chance to break soil.
You can also replace salt with Borax, which is very similar to salt but it’s alkaline based.
It’s commonly used in cleaners to kill bacteria, and it can help keep your garden weed free by killing off any especially stubborn weeds.
How Do The Ingredients Work?
On their own, the ingredients won’t be very effective in spite of what you may have read.
But when combined together, each ingredient in this homemade weed killer recipe plays a part in breaking down weeds.
- White vinegar is the most important ingredient. It’s heavily acidic, and it’s able to break down the cell walls of the weeds and deprive them of moisture. When this happens, the weeds cannot get the benefits of sunlight and water, two necessary elements for them to survive.
- The salt in the recipe will kill any remaining plants that the vinegar wasn’t able to eliminate. Salt is able to attack the plants and soil for longer than vinegar.
- Finally, the dish soap serves as a surfactant, meaning it allows the salt and vinegar to adhere to weed leaves and spread through the soil more easily. Dish soap can easily break down the waxy surface on some leaves. That is why it will increase how much of the vinegar and salt the weeds absorb.
You might have to experiment with the ratio of the ingredients if the weeds are more or less stubborn than usual.
Vinegar on its own might be able to kill weaker weeds, but household vinegar alone probably won’t be as effective against stubborn weed plants.
According to Noelle Orloff, an Extension Associate Specialist at Montana State University Extension, “Vinegar with a higher concentration of acetic acid tends to control weeds more effectively. Household vinegar is generally 5% acetic acid,” which is considerably less than the 20-30% acetic acid level you may see in herbicidal vinegar products.
This is why hardier weeds will need the full recipe I’ve shared to break them down. Using regular household vinegar will probably only be a temporary solution, and the weeds are likely to re-sprout.
Advantages of Homemade Weed Killer
A big advantage of homemade weed killer is that you aren’t using products that contain chemicals known to cause cancer and other dangerous stuff.
Chemical weed killers can be harmful to people and animals. A common component of the most popular non-selective herbicides on the market is glyphosate.
Homemade weed killers obviously don’t include this ingredient. The recipe I listed earlier, including regular white vinegar, salt, and dishwashing liquid are safe for kids and pets to be around if you spot-treat lawn weeds, or weeds in your garden.
That said, you should keep your dogs, cats, and any other pets away from your lawn for at least 24 hours after spraying the mixture.
This will allow the mixture adequate time to dissipate and absorb into the soil, and the garden will be safe again.
Animals tend to chew on grass, and we don’t want them ingesting a large amount of the solution, as they could get sick. Most won’t, because it would taste awful (I’m guessing here, but it would, right?), but it’s still better safe than sorry.
Another benefit of making your own natural weed killer is cost. You probably have all of these items in your kitchen already, so you can save yourself a trip to the hardware store and mix it up quickly without eating into your monthly budget.
Disadvantages of Homemade Weed Killer
The disadvantages of homemade weed killer are similar to some of the downsides of using chemical herbicides.
One is that this is a non-selective weedkiller … meaning it will kill pretty much any plant.
So you’ve got to be careful not to get any of the weed killer on the surrounding Turfgrass or your precious garden plants.
This risk increases significantly if you pour the mixture directly into the soil. It can spread much more easily, and other plant roots (including turfgrass and flowers) can soak it up and get damaged.
Another downside to this homemade weed killer is that it can hurt wild animals (such as deer) that come into your garden. Treated vegetation won’t be safe for a few days after application.
How And Where To Use DIY Weed Killer
The easiest way to use this DIY weed killer is to pour it into a spray bottle and then to spray it directly onto the weeds you hope to kill.
The vinegar usually only kills the top brush of weed, but the other two ingredients are able to go deeper and kill weeds at the root.
If the weeds you’re trying to kill are fully grown and well-established, I recommend pulling the weeds up by the root before spraying the area for best results.
As I mentioned, another way you can apply the mixture is by pouring it directly into the soil where the weeds are located. But remember — this could end up killing nearby grass and other plants.
Choose the Right Weather
You should apply the mixture to the weeds on a dry, sunny day.
Wet weather, such as rain or humidity, can cause the mixture to run off the weeds and not soak into the soil or weeds as it should, rendering it ineffective (or at least less-effective).
Re-Apply if Necessary After One Week
In my experience, the mixture usually kills off weeds within a week. You should reapply it whenever the weeds start to come back.
Another note I want to share is that less is more.
If you apply too much all at once, it could “shock” the soil and harm plants you don’t want to kill. Sometimes splitting a weed killer application into two applications is the best approach, and it’s usually the one I recommend for lasting results.
Take Care of the Soil
A few days after you’ve applied the weed killer, I recommend putting down a fresh batch of soil in the areas you’ve cleared of weeds. This will help replenish nutrients and allow fresh grass to grow in the area.
Watering the soil is also very important, to make sure it doesn’t dry out from all of the acidity.
Other Natural Weed Killer Options
A few other DIY weed killer options include household items like newspaper, lemon juice, and boiling water (I don’t need to share the recipe for this one, right?).
While it might sound odd, newspaper is such an effective natural weed killer that landscapers and gardeners have been using it for years. Here’s how
How to Use Newspaper to Kill Weeds
Once you pull up any stubborn weeds, lay down some newspaper on the soil.
It will block any new weeds from appearing or new weed seeds from forming by blocking out any sunlight or air, two main ingredients for plant growth.
You can also top it off with mulch or extra soil to ensure that weeds don’t re-appear.
Apply Lemon Juice
The acidity of lemon juice will break down the cell walls of weeds and dry them out.
To use lemon juice, put some in a spray bottle and saturate the patches of weeds on your lawn.
You can either squeeze some lemon juice from lemons on your kitchen counter, or buy it pre-prepared from the grocery store (but look for one that’s pure lemon juice).
If you want to make the lemon juice even more effective, mix a bit of white vinegar into the same spray bottle.
Doing so will amplify the acidity, so it will more easily break down stubborn weeds.
A Cheap, Easy Final Option
Finally, boiling water is ideal for weeds that appear in sidewalk or driveway cracks.
It’s very simple and inexpensive, but still quite effective against weaker weeds. Once the water comes to a rolling boil on the stove, carefully carry the pot outside and slowly pour the boiling water over the weed you want to kill.
I use this method mostly on gravel walkways and hardscaped areas where weeds are growing.
Is a Homemade Weed Killer Right For You?
So, now you know about the most effective DIY weed killers you can make at home.
If you have weeds on your lawn and want to avoid using chemical herbicides, consider using one or more of the solutions I’ve talked about here.
And if you’d like to learn more about some effective selective herbicides (that will kill weeds without harming your lawn’s grass), check out my list of the best lawn weed killers to explore your options.
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