How to Make Homemade Weed Killer

Making a homemade weed killer is cheaper than most store-bought options and avoids synthetic chemicals, but the recipe and timing matter more than most people realize. The strongest homemade option, horticultural vinegar with salt and dish soap, can kill most weeds within 24 hours, but it also kills your grass.

If you need a grass-safe, low‑toxicity product that helps prevent new weeds, corn gluten meal is the only option here. For established weeds in your lawn, Lawn Love’s local weed control pros can handle the hard cases while you maintain prevention at home.

How homemade weed killers work

Most DIY weed killer recipes kill weeds through one of 3 mechanisms:

• Contact damage: Acetic acid (vinegar) and alcohol rupture cell walls on contact, drying out leaves and stems. Roots are usually unaffected, so perennial weeds often regrow.
• Soil disruption: Salt, baking soda, and borax each change soil chemistry in different ways. They can raise pH, interfere with nutrient uptake, or build up toxic mineral levels, which can have lasting effects on nearby plants.
• Pre-emergent prevention: Corn gluten meal inhibits root formation in germinating seeds. It only works before weeds sprout, not on established plants.

Jessica Mercer, PhD, horticulturist at Plant Addicts in Omaha, Nebraska, says there’s a major limitation to these contact sprays.

“Homemade remedies typically do not kill perennials with deep taproots, like dandelions, dock, and thistle, or established woody shrubs and vines,” she says. “If sprayed on the leaves, the solution may burn the foliage but it will not move into the root system and kill the plant like a systemic herbicide does. Deep-rooted perennials and woody plants usually come back.”

To deal with these stubborn plants, Mercer recommends a different approach.

“For deep-rooted perennial weeds, I recommend repeatedly removing the top growth by mowing, pulling, or smothering to weaken the root system over time. If the weed is woody or invasive, physically removing the roots by hand digging is usually the most effective approach.”

Type	When to apply	How it works
Pre-emergent	Before weed seeds germinate (early spring)	Prevents root formation in sprouting seeds
Post-emergent	After weeds are visible	Kills existing plant tissue on contact or systemically

Which recipe is right for your situation?

Recipe	Effectiveness	Safe for grass?	Best for
Vinegar + salt solution	High	No	Driveway cracks, pavers, and young annual broadleaf weeds
Corn gluten meal	Low to medium	Yes	Preventing crabgrass; Annual grassy and broadleaf weeds
Essential oils + vinegar spray	Medium-high	No	Broadleaf weeds in garden beds (contact kill)
Borax	Low	No (avoid lawn)	Weeds in pavement cracks only
Rubbing alcohol	Medium	No	Young broadleaf weeds on pavement
Baking soda + water	Low	No	Young broadleaf seedlings
Boiling water	Low	No	Concrete or walkway cracks; Young weeds in cracks and pavement

Important: No homemade recipe selectively targets weeds while leaving established grass unharmed. For broadleaf weed control in lawns, a selective herbicide is the right tool.

Vinegar and salt solution

Overall success: High Best for: Young annual broadleaf weeds Herbicide type: Post-emergent Safe for grass: No

Horticultural vinegar (20%–30% acetic acid) combined with salt and dish soap is the strongest non-selective homemade weed killer widely available. It dehydrates plants and burns plant tissues, disrupting cell membranes.

“Natural does not automatically mean safe,” Mercer says. “Concentrated vinegar can burn skin and eyes, and salt can damage soil and surrounding plants even after the spray dries.”

Mercer says the biggest mistake people make is treating 20% horticultural vinegar like kitchen vinegar.

“It is strong enough to blister skin, injure eyes, harm soil life, and damage any plant it touches,” she explains. “Always wear gloves and eye protection and apply it carefully around desirable plants. Be careful using it on patios or driveways because repeated exposure can damage concrete.”

Adding salt can keep treated areas bare for months to several years by making the soil inhospitable, but it does not directly kill roots the way a systemic herbicide does.

“Salt lasts much longer in the soil than vinegar, up to several years, so only use it where you want nothing to grow, such as in driveway cracks or along hardscape edges,” Mercer warns. “Once salt builds up in a planting area, flushing it out can take a long time and is not always easy to correct.”

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 a strong acid, 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:

• Do: Apply to every weed leaf, as soon as weeds sprout, on a hot and dry day. Wear waterproof gloves and safety glasses.
• Avoid: Using in garden beds, near turf, in rain or wind, or near people and pets.

Corn gluten meal

Overall success: Low to medium Best for: Annual grassy weeds (including crabgrass) and broadleaf weeds  Herbicide type: Pre-emergent Safe for grass: Yes

Corn gluten meal is the only natural weed killer on this list that won’t damage your lawn. It interferes with root formation in germinating seeds while fertilizing grass with slow-release nitrogen.

“Corn gluten meal is a pre-emergent suppressant, so it must be applied when weeds are germinating from seed,” Mercer says. “It will not work on established weeds, and many common corn products, like cornmeal, corn flour, and cracked corn, do not have the right analysis to be weed suppressants.”

Effectiveness varies significantly by timing, application rate, and weather. The key is to apply before weeds germinate, and avoid applying right before heavy rain.

What you need:

• Corn gluten meal (60% to 65% protein)

Directions:

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

Application tips:

• Do: Pull visible weeds before applying, calibrate the spreader, and apply evenly on established lawns.
• Avoid: After overseeding, to new grass, to visible weeds, when the lawn is wet, before heavy rain, or overwatering.

Essential oils and vinegar spray

Overall success: Medium to high Best for: Broadleaf weeds in garden beds and pavement cracks (not in lawns) Herbicide type: Post-emergent How it works: Dehydrating plants, killing microbes, damaging plant tissue Safe for grass: No

This homemade weed killer recipe uses essential oils instead of straight vinegar, but it’s still a strong contact herbicide. Treat it like a pesticide and wear gloves and keep pets away until it’s dry.

Clove oil targets broadleaf weeds and soil microbes. Cinnamon oil is effective against redroot pigweed and wild mustard. Peppermint oil kills young weeds and 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:

• Do: Shake the sprayer, store in a dark-colored spray bottle in a cool place, apply on a sunny day, and wear gloves.
• Avoid: Using on turf, applying to wet weeds, spraying during heavy wind, right before a rainstorm, or letting it get on plants you want to keep.

Borax

Overall success: Low Best for: Occasional spot‑treatment of weeds in pavement cracks only Herbicide type: Post-emergent Safe for grass: No — avoid lawn application

Borax targets stubborn weeds using boron toxicity and sodium dehydration. Some homeowners use it to spot-treat their lawns, but this is a very bad idea.

Mercer says repeated use leads to lasting changes.

“Borax adds boron, a micronutrient that can be toxic if overapplied. These chemicals are best for weeds in pavement cracks, not in garden beds or anywhere you plan to plant later.”

What you need: 

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

Directions:

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

Application tips:

• Do: Apply early in the morning after the dew dries, apply a second round 2 weeks after the first application, wear safety glasses and long clothes.
• Avoid: Getting it on desirable plants, applying to turf, or using near children or pets.

Rubbing alcohol

Overall success: Medium Best for: Broadleaf weeds Herbicide type: Post-emergent Safe for grass: No

Diluted rubbing alcohol dehydrates weed tissue on contact. Use it only for driveway cracks and gravel, because repeated use can damage nearby plants and soil life. Don’t forget that rubbing alcohol is highly flammable.

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:

• Do: Apply with a cotton ball for precision on hot, sunny days. Wash it off immediately if any gets on the turf.
• Avoid: Applying when weeds are wet or before a rainstorm.

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 Safe for grass: No

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

Baking soda is still a salt that can upset soil and cause problems if overused. Since salt dries out plants and soil, many homeowners hone in on this homemade weed-killer spray. Like other salt-based substances, baking soda can linger in soil for months.

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:

• Do: Apply on a hot and sunny day and shake the bottle before applying.
• Avoid: Applying if your soil is already salty, right before heavy rain, or to high pH soil.

Boiling water

Overall success: Low Herbicide type: Post-emergent Best for: Young weeds with shallow roots Safe for grass: No

Boiling water is the easiest and cheapest homemade weed killer. It damages plant tissue but is non-selective and can harm any plant. It may permanently kill shallow-rooted weeds, but established perennials often regrow.

“Boiling water should be reserved for weeds in pavement cracks where there are no nearby roots you want to protect,” Mercer says.

“Occasional use on solid concrete or pavers is unlikely to cause much damage, but repeated use on asphalt, loose joints, or already weakened surfaces can lead to problems. The biggest hazard with boiling water, however, is the risk of splashing nearby plants or yourself,” she continues.

What you need:

• Boiling water

Directions:

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

 Application tips:

• Do: Apply with a tea kettle while the water is boiling, targeting small weeds in cracks.
• Avoid: Splashing boiling water on yourself or desirable plants.

FAQs

Skip the spraying and call a pro

If pesky weeds are an eyesore 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.

Main Image: A gardener spraying weed killer on a dandelion growing in a pathway. Photo Credit: dean / Adobe Stock