It's a common frustration: You've spent a warm, sunny day working in your garden, dutifully tilling the earth and planting seeds at just the right depth and distance — and then the next week, you go outside to find a crop of happy little dandelions enjoying your perfectly primed dirt. Of course, your first instinct is to destroy the invaders. So you get out your weed killer to take those dandelions to task.
Wait. Do you know what's in that weed killer? If it's full of chemicals you can't pronounce. Put it back on the shelf! Reach instead for something natural you probably already have in your house.
Why Is Natural Weed Killer Better?
For a green, healthy lifestyle, using chemical weed killers isn't the best choice. Not only can it be harmful to your environment and your health, but you can accidentally harm the rest of your plants and the surrounding soil.
Natural alternatives won't have any of the harsh toxic chemicals found in commercially available products.
Options to Kill Weeds Naturally
Pulling weeds by hand is generally the best solution to control any pesky plant problem, but really — who wants to labor on their hands and knees all day to dig rubbish out of the garden? Plus, it's just not as easy with small plants that travel, like clover and crabgrass.
You can try any of these more practical options to make weeding easier, keeping it all natural in the process.
Mow Your Weeds
A good, healthy lawn should never look like a golf course. Without daily maintenance, they'd be overrun with weeds! Don't let that happen to your yard. Mow your lawn high.
Pro tip: Set your blade height to 3.5 to 4 inches and mow as needed!
Using a lawn mower to cut your grass high keeps weeds at bay and grows a lush lawn perfect for barefoot walking. When you mow high, you aren't allowing "scalping," or damage caused by cutting the grass too short — this can lead to brown patches with no grass at all. You're also allowing the grass to grow a larger, more complex root system, which gives weeds less space to take over.
With longer grass, you're providing a shady soil surface — essentially blocking out the sunlight for any weeds that want to try and take hold.
How to Use: Set your lawnmower's blades at about 3.5 to 4 inches and mow as needed, with the bag attached. If you have a lot of weeds, removing the clippings prevents them from spreading seeds throughout the lawn. However, generally speaking, leaving the grass clippings on the lawn helps fertilize it.
The United States Department of Agriculture wanted to find out if vinegar (acetic acid) actually killed weeds. They commissioned a study, done by the Agricultural Research Service, to see if it's effective. Turns out, it is.
Did you know that vinegar will kill weeds within 2 weeks?
The study found that hand-spraying weeds with a 5 to 10 percent acetic acid concentration generally killed weeds within the first two weeks of them taking root. The higher concentration of 10 percent killed most weeds at every growth stage 85 to 100 percent of the time. For older weeds or ones with longer taproots, they needed a higher concentration, up to 20 percent.
How to Use: Add white vinegar to a spray bottle. Spray the weed, completely covering the visible portion with vinegar spray. Note that household vinegar is typically 4 to 7 percent acetic acid; anything higher is a specialty product and will require extra safety measures, like gloves and eye protection.
Burning weeds is also called "flame weeding." By hitting weeds with an intense burst of heat, but not setting them on fire, it damages the cellular structure of the weed.
Flame weeding works by damaging the cellular structure of weeds!
This isn't an immediate solution. Burned weeds don't die right away — often they take a few days to wilt and die. And you'll need to repeat the process on a schedule, too.
Many weeds have growing points underground or have a protective covering on the external parts of the plant that stop the flame from working right away. It's most effective on young weeds.
How to Use: Use a handheld torch and run the flame over each plant a couple of times. This is most effective when the weed is still a small sprout. Don't set them on fire, just burn them a bit. Repeat the process every few days for a couple of weeks.
Try Mulch or Straw
Mulching your soil has some great benefits. It moderates the dirt's temperature, keeps the soil moist, gives your plants much-needed nutrients, and — thankfully — keeps away the weeds.
Pro tip: Use a variety of materials to mulch — like wood chips or leaves!
When deciding what mulch to use, I recommend wood chips, straw, leaves, or grass clippings. Alternatively, you can go with fabric or newspaper, which blocks the sunlight from needy weeds. Avoid plastic, because when it breaks down over time, it adds toxic chemicals to the soil.
How to Use: Put a layer of newspaper down on your garden beds with holes cut out for the plants you want to grow. The paper will hold moisture to keep your plants healthy, and it will decompose and feed the soil. Cover it with 3 to 6 inches of organic mulch.
Pour Boiling Water
Using boiling water to kill weeds is so effective that one farming manufacturer developed a special type of machinery to do just that. It tows behind a tractor and sprays hot water onto the soil instead of herbicides. The machine reportedly works every time.
This method works best for weeds in sidewalks or driveways.
Luckily, you don't need a farm to do the same thing. Pouring boiling water over weeds will destroy them, all the way down to the roots. But it will also kill any other plant it touches. This method is particularly effective for cracks in sidewalks and driveways.
How to Use: Put the kettle on. When the water boils, spot-pour it onto weeds that are invading your lawn or garden. Be careful to only apply to weeds and not plants you want to keep. For weed control on larger patches, boil a pot of water on the stove and pour it over the plants.
Shade the Weeds
Warning: Shading weeds might be the most time-consuming process!
Shading weeds has an effect that's similar to mulch. Essentially, you cut off the light source so the weeds can't soak up any sun and grow to their full potential.
Most weeds need sunlight, and they can often outcompete ornamental plants, so if you cut off their source of sun in whatever manner, they will eventually lose out to your favored plants – however, this process may take time.
How to Use: For weeds that are just starting to grow, cover them with a light-blocking material like newspaper or fabric. Weigh it down with stones. For ones that have already grown high, cover them from above to block out the sunlight. For example, get two step stools and drape a tarp across them to provide strong shade.
Have you ever heard the phrase "salt the earth"? It's a good way to make sure nothing grows on that patch of land ever again — least of all, weeds. Salt is a natural desiccant, meaning it works really well to dry things out.
Pro tip: Be mindful of where you salt. Salting pulls all the moisture out of ALL plants!Putting salt on weeds pulls the moisture right out of the plant, essentially sucking it dry until there's nothing left for it to drink. Just be careful to salt weeds that are far away from anything you'd like to keep growing.
How to Use: Apply salted water over the weeds you want to kill, using at least a 1:3 ratio of table salt absorbed into the water. This is best for weeds in isolated spots, like sidewalk cracks. If you want to use this method in a garden, pour the saltwater through a funnel to direct it to the right plant.
Natural Weed Killer Recipes
To naturally get rid of weeds creeping around your yard and garden, you don't need harsh chemicals or a landscaper. All you really need is a quick trip to the grocery store. These three inexpensive homemade recipes are effective natural weed killers.
For each one, just mix all the ingredients in a one-gallon handheld sprayer; it should have a long nozzle and a manual air pump. You can find them at most hardware stores for about $10. Then use the nozzle to target-spray the weeds.
- 1 gallon vinegar
- 1 cup boric acid laundry detergent additive
- Note: Borax is the most common brand; it's a powder available at most grocery stores.
- 1 tablespoon natural dish soap, which acts as a surfactant
- 1 gallon vinegar
- 1 cup Epsom salt
- 30 drops of clove essential oil
- 20 drops of pine essential oil (optional)
- 4 ounces of citrus oil with D–limonene
- Note: Liquid concentrate of D–limonene is available online or at some health food stores, but runs $20–$30 for a 32-ounce bottle.
- 15-ounce bottle of real lemon juice
- Note: The bottles are available at most grocery stores for $2–$3.
- 12 cups of water
Commercial Weed Killer Ingredients to Avoid
This chemical sits in the middle of a debate about whether or not it causes cancer. Ask the Environmental Protection Agency and they'll say glyphosate is unlikely to cause cancer when used as directed. But according to the International Agency for Research on Cancer (IARC) glyphosate is a probable carcinogen and is also genotoxic, causing changes to DNA.
Not only that, studies have found the "inactive" ingredients and the total formulation of Roundup may be even more toxic than glyphosate itself.
Bottom line, avoid it. Other chemical herbicides to avoid include atrazine, diquat dibromide, picloram, 1-4 dioxane, 2-4-D (dichlorophenoxyacetic acid), and many others. You will find the best results in your health if you avoid toxic chemical herbicides altogether and instead use natural methods.
There's no use messing around with something that is toxic to yourself and your loved ones. In any case, if you ingest the chemical, you'll want to seek emergency medical attention.
Points to Remember
Introducing chemicals into your garden to kill weeds can have negative effects on both your other plants and your health. Natural weed killer is better because it doesn't have harsh toxic chemicals. For additional ideas, check out our organic gardening tips article!
For the simplest ways to kill weeds, mow your grass higher than you normally would, cover baby weeds with a light-blocking shade, or put down mulch.
If you're willing to put in slightly more effort, you can spot-kill weeds by pouring vinegar, boiling water, or saltwater directly on the ones you want to kill — but be careful you don't accidentally kill the surrounding plants you'd like to keep. You can also burn the weeds in your yard with a handheld torch, but you'll have to go over them a few times and be cautious of your surroundings.
To mix your own weed killer solution (instead of getting the toxic ones from the store), check out the three recipes above. You can make one with vinegar, salt, and essential oils; one with vinegar, Borax, and dish soap; or even one with citrus oil, lemon juice, and water. If you need more advice on dealing with garden pests, check out our organic pesticides article.
Have you tried a natural technique to kill weeds? Let us know what tips worked for you below!
- Smitley D. Mow High for Weed and Grub Control. Michigan State University Extension. Updated 8 Feb 2013. Accessed 7 Feb 2019.
- Comis D. Spray Weeds with Vinegar? United States Department of Agriculture. Updated 15 May 2002. Accessed 7 Feb 2019.
- Grubinger V. Flaming Stale Seedbeds for Weed Control. University of Vermont Extension. Updated May 2004. Accessed 7 Feb 2019.
- Mackenzie A. The Best Types of Mulch for Weeds. SF Gate. Accessed 7 Feb 2019.
- Machine Uses Boiling Water to Kill Weeds. FARM SHOW Magazine. Accessed 7 Feb 2019.
- Patterson S. Salt Recipe for Weeds – How to Use Salt to Kill Weeds. Gardening Know How. Updated 4 Apr 2018. Accessed 7 Feb 2019.
- EPA Releases Draft Risk Assessments for Glyphosate [news release].17 Dec 2017. Washington,US Environmental Protection Agency. Accessed 18 Mar 2019.
- IARC Monograph on Glyphosate. International Agency for research on Cancer, World Health Organization. Accessed 18 Mar 2019.
- Mesnage R, et al. Major pesticides are more toxic to human cells than their declared active principles. Biomed Res Int. 2014;2014:179691.
- Grass and Weed Killer Poisoning. MedlinePlus. National Library of Medicine. Updated 9 Jul 2017. Accessed 7 Feb 2019.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.