Despite the effectiveness of commercial weed killers, many people are skeptical of the environmental and health impacts that some herbicides may have. Also, with inflation impacting the cost of herbicides, many homeowners are looking for lower cost alternatives.
In fact, for these natural weed killers, you probably have everything you need already to make them! Sound too good to be true? Keep reading for our top five natural weed killer recipes.
1. Vinegar, Soap and Lemon Juice
When life give you lemons, make natural herbicide! That’s right, you can take care of those pesky weeds with some vinegar, castile soap and lemon juice.
For this recipe, measure 2 tablespoons of any natural castile soap and the juice of an entire lemon into a squirt bottle. Fill the rest of the squirt bottle with white vinegar. Shake the mixture and spray directly onto weeds. For a more powerful application, pour the mixture directly onto the weeds. The acidity of mixture will cause weeds to begin to die off over the next two weeks. If needed, apply again after three weeks.
Pro Tip: Use Horticultural Vinegar
For a more effective mixture, try using horticultural vinegar. Horticultural vinegar has a much higher concentration of acetic acid and will provide a much more concentrated solution. However, horticultural vinegar can irritate skin and impact soil health, so it should only be used when white vinegar doesn’t work.
Vinegar is effective at damaging the cuticle of most plants, but certain plants will actually benefit from the added acidity. The mixture is not likely to kill plants like hydrangeas or rhododendrons that thrive in acidic soil.
Why We Love Using Vinegar, Soap, and Lemon Juice As A Natural Weed Killer
First, vinegar has been scientifically proven to kill weeds. Second, using vinegar, lemon juice and soap is cheap and uses common household supplies. Also, making the solution is quick and foolproof, while still being highly effective at killing almost all plants. Vinegar can also be used to target specific weeds, if used properly, without significantly impacting the soil surrounding the plant.
Things to Consider
Using vinegar works so well that it might be too effective, depending on what you are using it for. It will kill almost all plants, so use caution when using in the garden to not apply it to any plants you are actively growing or would like to keep.
Also, perennial plants may require reapplication. The vinegar solution functions by causing the leaves of the plant to die off first. However, the roots will sometimes stay intact, allowing the plant to regrow within a few weeks, so a second or third application is sometimes necessary. For the same reason, vinegar may be less effective on perennial weeds that have an expansive root system beneath the soil.
2. Borax and Water
Borax isn’t just for cleaning; you can use it in your garden too. Sodium borate, also known as borax, is a naturally occurring mineral that is found in nearly every grocery store. It is highly alkaline, making the soil pH unsuitable for most plants. When used properly, it can be used to rid your garden of unwanted weeds.
For this recipe, mix ½ cup of borax with 1 gallon of water and spray, or paint, generously onto the leaves of unwanted plants. Be sure to wear gloves, long sleeves and safety goggles, as Borax can irritate your skin and eyes.
Spray directly onto unwanted plants in the garden, or more liberally in wider areas where you are not actively trying to grow plants.
Why We Love Using Borax And Water As A Natural Weed Killer
Borax is widely available, and making the solution is very simple. It is a highly effective and accessible option for those looking to reduce chemical herbicide use. Borax is also versatile and efficient at killing pretty much every unwanted plant and typically does not require reapplications.
Things to Consider
Borax can pose a health risk if inhaled, ingested, or spilled onto skin or clothes. So extra caution should be taken, because even though it is “natural” it can still be harmful. Also, sodium borate remains in the soil longer than other natural weed killers, so repetitive use can ruin soil quality, making the area unsuitable for plants in the future.
If you want to prevent weeds before they’re a problem, cornmeal is surprisingly effective. Cornmeal, or cornmeal gluten, smothers the seeds of unwanted plants, preventing them from even emerging from the soil. The cornmeal is not effective against every weed but is ideal for annual weeds without an existing root system such as chickweed, knotweed, crabgrass, and wood sorrel.
Use cornmeal gluten by applying generously on the soil where you want to prevent weeds. It will not work on fully mature plants but is ideal for preventing weeds in larger soil areas.
Why We Love Using Cornmeal As A Natural Weed Killer
With only one ingredient, using corn meal is incredibly cheap and only costs a few dollars. Plus, how much easier could it get? Cornmeal gluten prevents the problem before it’s even a problem, preventing loads of work later on. Cornmeal also is very safe to use and has little to no effect on the soil or surrounding plants.
Things to Consider
Cornmeal gluten only works on annual weeds that have not yet emerged from the soil. It has no effect on fully mature plants or perennial plants that have an established root network, as it does not actually penetrate the soil. So, if you’re looking to get rid of weeds that are already mature, this is not the best option.
4. Rubbing Alcohol and Soap
Another great option is using a simple solution of rubbing alcohol and castile soap. The rubbing alcohol works to damage the plant cuticle and dehydrate the plant and root system. The soap ensures that the rubbing alcohol attaches to the plant and functions properly. Rubbing alcohol is particularly useful for perennial weeds like dandelions, Canada thistle and quack grass which all have an existing root network.
To make this solution, combine 4 parts of rubbing alcohol to 1 part of castile soap in a spray bottle. Mix well and spray generously onto unwanted weeds. Try to avoid applying to the soil as much as possible.
Why We Love Rubbing Alcohol And Soap As A Natural Weed Killer
Rubbing alcohol is a cheap, quick fix that dehydrates the entire plant. The alcohol will damage a plant all the way down to its root system, making it highly efficient. When used correctly, it is an easy solution to get rid of weeds without requiring multiple applications.
Things to Consider
Rubbing alcohol is a strong mixture and, if allowed to permeate the soil, can impact the overall quality of the soil. This solution is best used in paved areas, like driveways and pathways, or places where you do not want any plants.
5. Boiling Water, Salt and Vinegar
When all else fails, start boiling a pot of water. A mixture of boiling water, salt and vinegar is incredibly effective at killing just about every plant. The damage from the heat, combined with the acidity of vinegar and the high sodium concentration in table salt is a lethal trio for plants. Especially helpful for paved areas, this solution will kill the plant and damage the root system beyond repair.
To make the solution, combine ¼ cup salt with ½ cup of vinegar in a medium pot and fill about ¾ of the way with water. Bring the solution to a boil and use a carafe to pour directly onto unwanted plants, being careful not to spill the solution on skin or clothes. This solution is best used on paved areas.
Why We Love Boiling Water, Salt, And Vinegar As A Natural Weed Killer
You probably have everything you need for this recipe in your kitchen cupboard. It’s also the most effective natural weed killer. The salt makes a big difference in drying out the root system of the plant, reducing the need for future reapplications.
Things To Consider
This solution is perfect for pavement, sidewalks and brick, but not the best for your lawn and garden. It dehydrates the root system of plants, but if used in a garden bed, the salt can damage the root system of all the plants in the bed. The salt also decreases soil health and can prevent future garden success.
Commercial pesticides are far from the only option for upkeeping your lawn and garden. Natural herbicides are the best option for ensuring a safer environment for you and your family. Harsh chemicals used in commercial pesticides have been linked to multiple health ailments and pose risks for long-term health risks. These harsh chemicals linger in the soil much longer than natural herbicides and can affect the development of plants in the soil for years after application.
Making natural herbicides allow you to know exactly what goes into your garden. The first step to taking control of your garden is finding what the best recipe is for each area. Start by deciding whether or not you want to eliminate all the plants in an area, or if you would like to be selective in which plants stay and which ones need to go.
Then, decide which solution is the most feasible to make. Take into account what ingredients you already have on hand and compare the costs of different natural herbicides. Not every recipe will work for every situation but start by testing different solutions around your garden.