So which method is better?

It depends on the location.

For Patio Cracks

Vinegar can be convenient for small weeds.

For a Flower Bed

Hand pulling is usually safer.

For Large Perennial Weeds

Vinegar alone is unlikely to provide reliable long-term control.

For a Lawn

Don’t use a non-selective vinegar spray unless you’re intentionally trying to kill the grass too.

That’s an important point: vinegar doesn’t distinguish between weeds and lawn grass.

What About Boiling Water?

Boiling water is another popular homemade weed-control method.

It can damage young weeds when poured directly over them, making it useful for cracks in sidewalks, driveways, and other hardscape areas.

But just like vinegar, it isn’t selective.

If you pour boiling water over the roots of a nearby plant, that plant can be damaged too.

It also generally won’t solve the problem of large perennial weeds permanently.

Why This DIY Recipe Isn’t a Replacement for Every Herbicide

It’s tempting to think that because vinegar is a kitchen ingredient, it must be a safer or more effective alternative to commercial weed killers.

That’s not necessarily true.

Household vinegar is relatively weak and works primarily as a contact treatment.

Commercial herbicides are formulated for specific weeds, application methods, and situations. Some are designed to move into the plant and provide more systemic control.

That doesn’t mean you need to use a commercial herbicide for every weed.

It means you should choose your method based on the weed, the location, and the result you actually want.

Common Mistakes to Avoid

Adding Lots of Salt

More salt isn’t automatically better.

It can make the treatment harder on your soil and nearby vegetation.

Spraying Everything

A homemade weed killer should be targeted.

Don’t treat an entire garden when you only have a few weeds.

Expecting One Application to Kill Deep Roots

If the plant has a substantial underground root system, expect the possibility of regrowth.

Spraying on a Windy Day

Even a small amount of drift can damage nearby plants.

Using Strong Vinegar Without Protection

High-concentration acetic acid is much more hazardous than ordinary kitchen vinegar. Follow the product label and use appropriate protective equipment.

The Nana Test: Is This Old Trick Actually Worth Using?

Yes—with a few important qualifications.

The old vinegar trick isn’t completely made up.

Vinegar really can damage and kill small weeds.

But the internet version often oversells what it can accomplish.

It isn’t a permanent cure for every weed, it doesn’t reliably kill established perennial roots, and adding salt can create unnecessary soil problems.

The smartest version of the old trick is therefore much simpler:

Use a targeted vinegar treatment for small weeds in hardscape areas, leave the salt out when soil health matters, and use hand pulling or mulch around plants you want to keep.

Frequently Asked Questions

Does vinegar really kill weeds?

Yes. Household vinegar can damage the foliage of small, susceptible weeds. However, it often doesn’t kill the roots of established perennial weeds, so regrowth is common.

Does adding dish soap make vinegar more effective?

Dish soap can help the solution spread and remain on leaf surfaces. Its role is primarily as a surfactant rather than as the main weed-killing ingredient.

Should I add salt?

For areas where you want plants to continue growing, it’s better not to. Salt can damage soil and nearby vegetation, especially with repeated use.

Can I use this around flowers?

It’s best to avoid it. Vinegar is non-selective and can damage desirable plants if it contacts their foliage.

Will vinegar kill dandelions permanently?

Usually not with household vinegar alone. It can burn back the leaves, but established perennial weeds can regrow from their roots.

Is horticultural vinegar the same as kitchen vinegar?

No. Horticultural vinegar can contain much higher concentrations of acetic acid and can be considerably more hazardous to handle.

What’s the safest homemade method for weeds in a flower bed?

Hand pulling, hoeing, and mulch are generally better choices because they avoid spraying a non-selective substance onto plants you want to keep.

Final Takeaway

Your nana wasn’t completely wrong.

A vinegar-based weed killer can work, especially on small annual weeds growing in places such as driveway cracks, patios, and other areas where you don’t want vegetation.

But the secret isn’t some magical three-ingredient formula.

The real trick is knowing where it belongs and where it doesn’t.

Use vinegar as a targeted contact treatment, don’t expect it to permanently eliminate deep-rooted perennial weeds, and think twice before adding salt to soil that you want to keep healthy.

For garden beds, flowers, vegetables, and around trees, good old-fashioned pulling and mulch may save you more trouble in the long run.