The Easiest Chemical-Free Way To Kill Weeds

The Easiest Chemical-Free Way To Kill Weeds

We constantly wage war on weeds. Instead of using commercial weed killer to eliminate those pesky weeds, we looked for more eco-friendly and cheap solutions and put them to the test to see which was best. Here are the results.

Photo by Hermann Kaser

In this experiment, I tried three solutions: boiling water, white vinegar, and vinegar with some salt mixed in, and sprayed these to two areas with different kinds of weeds.


This is what the two areas looked like at the start. Lovely, right?



Boiling Water: The Instant Weed Killer

This is what the first area looked like right after spraying one side with vinegar and pouring boiling water on the other. You can see how fast the boiling water worked. The weeds started to turn brown right away. The vinegar-sprayed side, however, showed no change (not that I expected any that fast.


Two days later, the area sprayed with vinegar did die off a little, but not as much as the boiling water part. I had read somewhere that adding salt to vinegar would increase the solution’s weed-killing powers, but that actually wasn’t the case here. That side seemed to grow even more weedier. Do not feed your weeds vinegar and salt!


Area two shows the same results: Boiling water killed the weeds, but the vinegar was a bust. Today, a few weeks later, the areas treated with boiling water still have no weeds growing, thankfully.

Know of any other chemical-free ways to keep weeds at bay?


  • The boiling water thing certainly works. However, it has to be and remain sunny for it to work, otherwise, as my Mother discovered, all you are doing is watering them. Boiling salty water might be doubly good in paved areas where you don’t want anything to grow.

      • It’s ridiculous that whole chemical free fad. Mainly used by green types and pseudo-scientists.
        Also using salt will raise the salinity levels of the soil and be very hard to repair when you want to plant plants there.

    • Thank you! I’m glad somebody mention that. The tag “chemical free” is my number one “push button” issue with science illiteracy.

    • Water is not a chemical. It is simply a compound of two hydrogen atoms bonding with one oxygen. It occurs naturally and not by human tampering; it is a solution or a compound but it isn’t a chemical.

      • Water is a compound, which is a chemical. It is a solvent, and only becomes a solution when you dissolve a solute in it. Salt and vinegar are both residual chems, as has been pointed out, and are ecologically more damaging than many commercially produced herbicides. As a greenie, scientist & weed control contractor, I spray many different chemicals to solve weed problems. I am not always comfortable with it, but I would find it unconscionable to hose out salt & vinegar, & embarrassingly inefficient to use boiling water.

  • Yeah, a $7 bag of pool salt is a petty effective weed killer that stops them coming back for ages. Sprinkle over area to kill and water it in a bit.

  • During the summer, putting black polythene sheets over the weeds for a few days kills most weeds (it cooks them) but the problem with this method is weeds with deep roots. Glyphosate is the best safe(ish) weed killer to use for thosetypes. Alternatively, get yourself a goat!

  • Salt should be great for paved areas, and should last a while, just be careful you don’t get run off that affects other plants. The flame treatment does work but needs a few more applications and careful you don’t set mulches alight. In reality glyphosate products like round-up are safe, it deactivates as soon as it hits any soil, is safe to aquatic life and the average man needs to drink somewhere in the range of 50L of undiluted, agricultural grade product for it to kill them. It’s not the bad stuff everyone makes it out to be.

      Why do you think the entire country of France has BANNED the use of Roundup?
      Why do you think glyphosate is so DANEROUS?
      Why do you think there is a CLASS ACTION LAWSUIT against Monsanto/Roundup for FALSE ADVERTISING?

      • Be a man and don’t house behind a guest account.

        The french banned it from backyard use only. It is still available for commercial use. Also is not unusual for different countries to have different standards when it comes to agricultural chemicals. It is common for one country to set one MRL, another to set their’s lower, one to set MRL at zero and a fourth to have no MRL at all. None are wrong.

        I’m not denying it is dangerous, evening is in the right (wrong) dose, but I’ll assume you’re talking about the recent classification as a possible carcinogen. The key word there is possible, it is in the same category as caffeine.
        While we’re at it, caffeine can be used as a herbicide, it would fall into the pre-emergant category as it prevents seed germination. Vinegar also has herbicide actions as well.

  • That is not true. Ingestion of less than 100ml of roundup has been known to cause death. It’s not as biodegradable as claimed either. if you look at recent packaging, the biodegradability claim has been removed. It is a toxic product, and teratogen.

  • I saw a guy with a steam-based weed killer a few years ago. It had like an upside-down funnel that you placed over the weed, pressed a button, and steam got pumped over the weed. Because of the funnel, I’d guess there was a bit of pressure to force the steam down into the ground a little bit.
    It looked quite simple and effective…

  • One of my mates is a welder by trade and he reckons an Oxy Acetylene torch is an extremely effective everything killer.

    Weeds, houses, steel, aluminum, hard drives, SSD’s, flash drives, portable hard drives, cars, tyres, dead pets, yep, there’s practically nothing it can’t get rid of.

  • I’ve tried boiling water and it appeared to work, BUT … it took 4 litres to treat just my modest brick driveway; would have taken several times that to do everywhere. Also the weeds didn’t stay dead as long as with Roundup, so frequent boil-ups would have been needed.

    So while water may be simple and non-toxic, it isn’t without extra costs in time, and especially electricity to boil all that water. And for most of us electricity means the burning of coal. Eco-friendly? Not 100%

  • My brother in law introduced me to a butane weed wand. You don’t try to burn them and blast them off the face of the planet, but rather cook the weeks until they’re all droopy. Seems to keep them away for a month or two. Much better for wife and child with chemical sensitivities (wife can’t even walk down the detergent isle in Coles without getting a headache). I seem to recall I bought it online from a hardware store in melbourne and they posted to sydney, couldn’t find it at bunnings.

    I’m not sure if it’s the *BEST* solution, but in terms of sheer satisfaction, wandering round the garden with a cold beer in one hand and a mini flamethrower in the other does bring a certain kind of contentment that only Calvin can understand…

  • @browndog You should check your sources: Ingestion of Roundup ranging from 85 to 200 ml (of 41% solution) has resulted in death within hours of ingestion.

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