How to Make Homemade Weed Killer

Our homemade weed killer recipes are easy to make. They contain common cupboard ingredients, like vinegar, water, and salt. Simply mix the ingredients, then apply with a sprayer or fertilizer spreader. 

For successful organic weed control, choose a recipe that targets the weeds you want to kill. With the help of University researchers and industry experts, we provide the ins and outs of each budget-friendly recipe. We include the best weeds to target and application tips. 

Science behind how natural weed killers work

Most natural weed-killer recipes work in one or more of the following ways:

• Smoothing weeds: Without light, photosynthesis comes to a screeching halt. Unable to synthesize their food, weeds typically die within 4 weeks. 

• Dehydrating plants: There are organic ingredients that rupture cell walls on contact, letting moisture leak out of the plant’s tissue. Some substances also dry out plant roots.
• Changing soil pH: Each plant prefers a particular pH, so changing the soil’s pH often impedes survival. Most vegetation thrives with a pH between 6 and 7, but others prefer a higher or lower acidity.
• Killing microbes: Healthy microbes make soil self-sustainable. These organisms move around, loosening soil, then become fertilizer when they die. Killing microbes compacts your soil, making it hard for weeds to absorb water and nutrients. It also offsets the earth’s natural ecosystem. 
• Poisoning plants: Natural weed killers sometimes contain ingredients that make the soil poisonous to particular plants. For example, some weeds decline when you oversaturate the soil with a distinct mineral. 
• Damaging plant tissue: Many plants have a waxy outer layer that provides them with protection. Many homemade weed killers break down this layer, opening the door to their demise. 

Our recipes include both pre-emergent and post-emergent herbicides. Apply pre-emergent herbicides before weeds sprout and post-emergents to existing weeds. 

Most effective homemade weed-killer recipes

After years of weed control strife, we found what kills weeds permanently and naturally. Through research, personal practice, and debate, I picked the most effective homemade recipes. Rest assured, the following recipes are chemical-free solutions that really work. 

Vinegar and salt solution 

Overall success: High Best for: Young annual broadleaf weeds Herbicide type: Post-emergent How it works: Dehydrating plants, killing microbes, lowering soil pH, damaging plant tissue My tip: I recommend vinegar-salt spray to control weeds in driveway cracks and gravel

My vinegar weed killer is the perfect natural alternative to toxic roundup. It uses horticultural vinegar to kill weeds and quickly affects any plant it touches, typically within a day. In addition to eliminating existing vegetation, it inhibits future germination for up to six months. It’s a potent natural weed-killer spray because each ingredient plays its part:

Vinegar contains acetic acid, which dehydrates the parts of the plant it touches (e.g., leaves and stems). However, vinegar’s harmless to parts it doesn’t touch (e.g., roots), and new seeds can sprout from treated soil after a couple of days.

Salt brings death to the soil by dehydrating plants, massacring microbes, and altering the soil’s pH. So, adding salt to the solution makes it better at permanently killing weeds and hindering future growth. 

Dish soap is a surfactant that helps the vinegar and salt attach to the weed’s leaves. Additionally, it aids in drying out plants.

What you need:

• 1 gallon of horticultural vinegar
• 1  tablespoon of dish soap
• 1 cup of table salt

Directions:

1. Mix the ingredients until the solution is uniform.
2. Apply with a garden sprayer. 

Important safety note: Since the solution contains strong acid, please follow a keen safety protocol. Cover your skin and eyes, and store the vinegar spray away from children and pets. Also, avoid inhaling its vapors by only handling it in open outdoor spaces. 

Application tips	What to avoid
✓ Apply to every weed leaf	✗ Don’t apply in garden beds
✓ Apply on a hot, dry, sunny day	✗ Don’t apply near turf
✓ Apply as soon as you see weeds sprout	✗ Don’t apply when it’s raining
✓ Wear waterproof gloves	✗ Don’t apply when it’s windy
✓ Wear safety glasses	✗ Don’t apply near people or pets

Corn gluten meal

Overall success: Medium to high Best for: Annual grassy weeds (including crabgrass) and broadleaf weeds  Herbicide type: Pre-emergent How it works: Dehydrating plants, while fertilizing grass with slow-release nitrogen My tip: Most spring weeds sprout when the soil’s 50 to 59 degrees. Monitor the soil temperature to make sure you apply corn gluten meal before weeds emerge.

Corn gluten meal is one of the best natural weed killers for lawns. You can apply it up to three times a year, with increased success rates after each application:

• First application: 50%
• Second application: 75%
• Third application: > 90%

It targets weeds before they sprout, so they never show their ugly faces in your turf. Additionally, it feeds grass a healthy helping of slow-release nitrogen. Hence, it’s often called nature’s weed and feed.

Remember, this organic lawn weed killer is only practical if applied before weeds germinate. Once seeds sprout, corn gluten meal doesn’t hurt them. On the contrary, it helps nitrogen-loving weeds grow. But rejoice because it’s the best pre-emergent herbicide that’s organic and safe for grass.

What you need: 

• Corn gluten meal (60 to 65% protein)

Directions:

1. Use a fertilizer spreader to apply the granules. 
2. Then, gently water the lawn to activate, only applying about ¼-inch of water. 

Application tips	What to avoid
✓ Before applying, pull any visible weeds	✗ Don’t apply after overseeding
✓ Before applying, properly calibrate the spreader	✗ Don’t apply to new grass
✓ Apply evenly	✗ Don’t apply to visible weeds
✓ Only apply on established lawns	✗ Don’t apply when the lawn’s wet
✓ Apply around 20 pounds per 1,000 square feet	✗ Don’t apply if expecting heavy rain
	✗ Don’t overwater

Essential oils and vinegar spray

Overall success: Medium to high Best for: Broadleaf weeds, ryegrass, redroot pigweed, wild mustard, flies, ants, spiders Herbicide type: Post-emergent How it works: Dehydrating plants, killing microbes, damaging plant tissue

This homemade weed killer recipe smells pretty and works wonders on many predominant pests. It’s also non-toxic, easy to use, and one of the best post-emergent herbicides. 

It works like magic, with a little help from each ingredient. Clove oil is one of the most potent essential oil herbicides, targeting broadleaf weeds and soil microbes. Cinnamon oil is a powerful pesticide that’s most effective against redroot, pigweed, and wild mustard. 

Peppermint oil kills young annual weeds and insects. Plus, it prevents ryegrass seeds from germinating. White vinegar dehydrates plants and is most effective at broadleaf weed control. Finally, add dish soap so the formula sticks to your weeds.

What you need: 

• 10 drops of clove oil
• 10 drops of peppermint oil
• 10 drops of cinnamon oil
• 4 cups of white distilled vinegar
• 1 tablespoon of dish soap

Directions:

1. Mix the ingredients until uniform
2. Apply with a sprayer. 

Application tips	What to avoid
✓ Before applying, shake the sprayer	✗ Don’t let it get on plants you want to keep
✓ Apply and store in a dark colored spray bottle	✗ Don’t apply to turf
✓ Apply on a hot, sunny day	✗ Don’t apply if the weeds are wet
✓ Wear gloves if you have sensitive skin	✗ Don’t apply during heavy wind
✓ Store in a dark, cool place	✗ Don’t apply right before a rainstorm

Borax

Overall success: Medium Best for: Ground ivy, broadleaf weeds, ants, flies Herbicide type: Post-emergent How it works: Dehydrating plants, poisoning plants, killing microbes

Borax is nature’s sword for slaying some of Earth’s most stubborn pests. The naturally occurring compound commonly combats ground ivy and insects. Borax contains the following weed-killing components:

• Boron is a nutrient that plants need in tiny doses, but excessive amounts are toxic.
• Sodium dehydrates plants and kills microbes.

Some homeowners use it to spot-treat their lawns. However, researchers from Iowa State University and the University of Wisconsin have raised concerns about its effects on your soil, as the formula can leave impacts for up to 6 months.

What you need: 

• 1 ¼ cups of Borax (laundry powder)
• 1 gallon hot water

Directions:

1. Mix Borax with hot water until it completely dissolves. 
2. Then, apply it with a sprayer. 

Application tips	What to avoid
✓ Apply early in the morning, after the dew dries	✗ Don’t let it get on plants you want to keep
✓ Apply a second round 2 weeks after the first application	✗ Don’t put it on turf
✓ Wear safety glasses	✗ Don’t apply near children or pets
✓ Wear clothes that cover your skin

Rubbing alcohol

Overall success: Medium Best for: Broadleaf weeds Herbicide type: Post-emergent How it works: Dehydrating plants, damaging plant tissue

We recommend rubbing alcohol for treating driveway cracks and gravel, but not for lawns or gardens. The DIY weed killer degrades soil, harming anything that grows in it. 

What you need: 

• 1 quart of water
• 2 tablespoons of rubbing alcohol

Directions: 

1. Mix the rubbing alcohol and water
2. Apply it with a garden sprayer. 

Application tips	What to avoid
✓ Apply with a cotton ball to be more precise	✗ Don’t apply if the weeds are wet
✓ Apply on hot, sunny days	✗ Don’t apply right before a rainstorm
✓ While applying, if any gets on the turf, stop and wash it off immediately

Baking soda and water

Overall success: Low  Best for: Young broadleaf weeds Herbicide type: Post-emergent How it works: Dehydrating plants, killing microbes, raising soil pH

This mixture only harms plant parts that it touches. Typically it only kills young broadleaf weeds, but can cause decline in any plant. 

Diluted baking soda is safe around children and pets. Although non-toxic, it contains a lot of salt. Since salt dries out plants and soil, many homeowners hone in on this homemade weed-killer spray.

What you need: 

• 1 cup of baking soda
• 1 gallon of water

Directions:

1. Mix the solution until all the baking soda dissolves. 
2. Then, apply it with a spray bottle. 

Application tips	What to avoid
✓ Before applying, shake the bottle	✗ Don’t apply if your soil’s already salty
✓ Apply on a hot, sunny day	✗ Don’t apply right before heavy rain
	✗ Don’t apply to soil with an overly high pH

Boiling water

Overall success: Low Herbicide type: Post-emergent Best for: Young weeds with shallow roots How it works: Damaging plant tissue

Boiling water is the easiest homemade weed-killer recipe. It’s also the cheapest. Since it’s non-selective, boiling water can damage any plant. However, it can’t permanently kill most weeds.

Aaron Steil of Iowa State University says, “Pouring boiling water on weeds can be used especially in situations where other plants are not nearby, such as in cracks in patios or sidewalks. Boiling water will act as a contact herbicide, killing only the portion of the plant it comes in contact with.”

Expect to see a visible decline within a few hours. Some leaves will immediately start to turn brown, but many plants require multiple applications. 

What you need:

• Boiling water

Directions:

1. Boil water
2. Pour it directly on unwanted weeds. 

Application tips	What to avoid
✓ Apply with a tea kettle to make precise applications	✗ Don’t splash boiling water on you, or anyone else
✓ Apply as soon as you see a weed sprout	✗ Don’t pour water on any desirable plants
✓ Apply water that’s 212 degrees or hotter

Other ways to get rid of weeds

Some of the best natural weed killers aren’t even herbicides. Here are some other methods of non-toxic weed control:

• Mulch: Weed control is one of the many benefits of mulch. Add a thick layer to garden beds to smother incoming weeds. There are many types of mulch to choose from, but I recommend organic mulch.
• Landscape fabric: One of my favorite natural weed smoothers is landscape fabric. Putting it beneath mulch prevents most weeds from surfacing. If truth be told, I’ve only seen thick, woody weeds break through.
• Landscape edging: Place landscape edging around garden beds to provide a barrier, making it more difficult for weeds to infiltrate the bed. Recycled rubber is one of the best barriers. It works well alongside mulch and landscaping fabric. 
• Hand pulling: Pull out the entire weed, including roots and taproots, so the weed can’t grow back. The younger the weed is, the easier it is to achieve a clean pull.
• Groundcovers: They are another natural weed-smotherer. Like mother nature’s blank, groundcovers softly cover the ground, providing warmth to the soil. They also block several weeds from sprouting.
• Solarization: Cover the ground with a plastic sheet and leave it there for 6 to 8 weeks. The process of solarization controls weeds using the sun’s heat. Soil gets as hot as 140 degrees Fahrenheit, killing the plants beneath the plastic. 

FAQ about homemade weed killer

When to call a weed control pro

If pesky weeds are an eye soar in your lawn, it’s time to call a weed control pro. Since regular mowing is one of the best cultural practices for controlling weeds, we also recommend hiring a pro for routine lawn care.

Lawn Love connects you with qualified outdoor service experts. Our app makes it easy to find local pros with insurance and affordable rates. It only takes a couple of mouse clicks to make your lawn lovely and lush. 

Lawn Love participates in the Amazon Services LLC Associates Program and other retailer affiliate programs. Lawn Love earns revenue from products promoted in this article.

Main Image Credit: dean | Adobe Stock