Killing Weeds with Hot Water

Here is an easy method for getting rid of weeds in sidewalk cracks and between patio stones. I’ve found it to be very effective, and it’s completely non-toxic. I use boiling hot water for killing weeds in the gaps, and have found it to be very successful at removing just about all of the weeds. You can see in the pictures below how well it works.

I carry the boiling water into a coffee carafe with a lid and pour spout for safety. It wouldn’t be a safe idea to be moving open pots of boiling water. I wear enclosed boots for safety. I also make sure to pour it down low and away from myself, so it doesn’t splash up, while killing the weeds.

I just pour the boiling water on the weeds in the cracks, and most look like cooked vegetables a few hours later. Most weeds are dead the next day. I’ve found a few established weeds might need a second treatment, if they haven’t died in a few days.

I usually use this method of killing weeds in early summer, but it’s a little later this summer, so some of the weeds got a little big before the boiling water treatment. Within a few days, the weeds have usually crumpled into tiny dessicated pieces that disappear. A week or so later, you hardly see anything left.

Here are some before and after shots of the weeds that were killed in my sidewalk and driveway. The old weed on the top half, and the dead weed on the bottom half. I should have set up little signs, as after a day it was much harder to recognize individual weeds.

weeds before and after boiling water
weeds before and after boiling water

Here is a before and after photo of the weed killing in action. The bottom of the picture was taken 4 hours after the boiling water was applied. You can see how quickly this one died.

weeds before and after boiling water 3
weeds before and after boiling water 3

The bottom half shows the pineapple weed the day after applying the boiling water to kill the weed. This might not be the exact same pineapple weed as I had trouble matching up the dessicated leaves. Within a day they are dried up and breaking down after the boiling water kills them.

weeds before and after boiling water 2
weeds before and after boiling water 2

This shows another weed, knotweed, before and 2 days later, now dead after the boiling water application.

I usually apply the boiling water once in early summer, and that’s all that’s needed for the season. It’s highly effective at killing weeds. I don’t know if those with a longer growing season might need to do it more than once. I’ve been using the boiling water method for 3 years and have been very pleased with the results.

What I like about this method of killing weeds is that it is completely safe for the environment, your family and animals, with no toxic lingering effects. It is perfectly safe for pedestrians and pets walking down the sidewalk in front of my house. Using boiling water is the fastest, easiest and most non-toxic method for weed killing between patio stones, driveway sections and sidewalk blocks.

98 thoughts on “Killing Weeds with Hot Water”

    1. Helen, it’s very effective and much easier on the fingers than hand pulling against the cement. I don’t mind hand pulling weeds in the soft soil of the garden beds, but my fingers used to get scratched up from pulling the weeds out from between the gaps in the cement. It used to take me hours to pull them from all of the walkways and paths.

      Joanne, when I use boiling water on the walkway cracks next to the garden, I hold a barrier at the end of the crack, so the water doesn’t run into the garden bed.

    2. That’s awesome however, I have a lawn full of red ants and want to kill them. Will I kill the grass as well?

  1. Wonderful idea!! And great pictures to prove it works. Do you remove the dead plants, or do they go away on their own?

    1. Rebecca, they mostly dessicate, shrivel into tiny pieces, and are gone within a week. That makes it especially easy. A couple of extra large dead weeds might have to be removed later if they haven’t disintegrated.

  2. I have heard of this one before but I’m so glad you wrote about it .. apparently it got stuck in my “vault” and I forgot until I read this and said “Oh yeah !!” haha
    We don’t use any chemicals here now … I do a lot of manual labor on weeds and some how digging them up is a great stress buster .. go figure ? haha
    Great post girl !

    1. Joy, I like hand weeding in the garden beds too. It does have a certain satisfaction, and if you start early, have your plants fairly close, or use mulch, it doesn’t get too bad.

      I really disliked hand weeding from between the cement spaces of the walkways, driveway and front sidewalk, though. It would take me so many hours, and my finger tips would get scraped raw against the cement. The boiling water is so much faster and easier.

  3. i have a weed that is like a vine and wraps itself aroung my fence or other garden plants and flowers, any suggestions

    1. Obrien, weeds can be very frustrating when they have become established like your vine. I’ve only ever used the boiling water method on the weeds in my sidewalk gaps. I hand pull the weeds in my garden beds, but if you have a weed with long runners or roots, it takes a lot of persistence. I don’t like to use chemical weed killers, since so many of them have negative health effects on people and animals.

  4. I’ve being walking past some dandelions in my front paving for the last few weeks muttering that I must dig them out…and then forgetting. I’ve just boiled some water so I’m off to test your method!

    1. Easygardener, I’ve found the boiling water so much faster and easier than trying to dig them out of the cracks, especially if you have a lot of paving gaps. I have almost no new weeds grow afterwards.

  5. Every time I try to weed the cracks between the stones, ants bite my ankles. My teakettle is going to become a lethal weapon. I’m thinking a little ant soup to go with weed tea will hit the spot. Thanks for the HOT idea!

  6. Excellent advice! Killing weeds with boiling water is ever so simple yet effective. It is one of the methods I’ve tooted for years but is now getting a bit more attention with Ontario’s new pesticide ban. I love how you used the before and after pictures to illustrate how effective this method is.

    1. Garden Gnome Wanderings, good for Ontario for banning pesticides and herbicides for cosmetic reasons. I’m sure that 10 or 20 years from now, people will look back in disbelief that homeowners actually used to poison their own property for such minor reasons.

      Thanks for adding my blog as a favourite.

  7. This is the perfect solution for the cracks in my driveway! I do have to remind my plant sitter to let the hot water clear out of the hose before watering or the plants would die. gail

    1. Gail, I have a grid of expansion gaps in my driveway, and this works very well to kill the line of weeds. I used to have trouble getting my fingers into the little gaps to get a good hold on the weeds. This is so much easier.

      Plant Lady, when I use the boiling water on the spaces in the walkway near my garden bed, I put a barrier at the end of the gap so the water doesn’t accidentally flow onto the garden.

  8. I’ve not heard of this method & as soon as I’m done typing will go boil water! I have a few graveled paths I put off weeding until it’s so too late! Then the snow flies & I pretend I don’t have to deal with it until the next year. Thanks!!

  9. Nice blog! Thanks for posting this valuable info. I’d heard about the boiling water treatment, but never seen proof before. Thanks so much! -Jackie

    1. Jackie, it doesn’t take long for most weeds to start appearing dried and dessicated. Most look dead in the first few hours. A couple of days later there are just pieces of withered leaves, and in a week, they will have mostly disappeared.

  10. Since we’re on the topic of getting rid of unwanted ‘pests’, have you had any problems with slugs? I a few plants in my shady/moist areas are getting chomped. I bought some Safer’s Slug Bait, but have since read about using coffee. Just wondering if you have any experience with either? :)

    1. I am reading this for the first time and am trying it. As for slug problems my dad use to take a shallow plate and pour some beer in it. The slugs like beer or something in it. They go drink it and drowned in the beer. Worked for him in wisconsin. Might help.

    1. Frugilegus, it’s very satisfying when they all look like the after photos (although I have to grudgingly admire plants that are willing to put up with the conditions in a sidewalk crack in order to grow).

  11. What a fantastic tip. I have tried it today, and it really works. I have quite a big gravel driveway, and I’ve been struggling to control the weeds, so this has been a revelation to me! There is also an excellent side effect – the boiling water makes the soil underneath wet AND warm, so some taller weeds, and grass, can be pulled up more or less straight away by the roots. Great for me as I am too impatient to wait even one day!

    1. Belga, I’m glad it made it easier to get rid of the weeds in your gravel driveway, and there are no toxic after effects. It seems to kill the seeds on the top too, so I don’t usually have new weeds appearing in that season.

    1. Barbara, I use boiling water to kill the weeds between my patio stones, and it works very well. This non-toxic method is safe, and it’s reassuring to know that you’re not poisoning your land or the animals.

  12. Excellent tip. The photo’s say it all. Just wanted to share that a Canadian company (ours -yes, shameless plug) is shipping steam weeders big enough to enable city workers, schools, etc. to do the same thing on the miles of cracks they are responsible for. And in terms of what we can all do to help, whenever we see someone spraying sidewalks with a chemical back pack at 6 a.m. (to avoid your prying eyes and wind drift) we can can do more than grumble, we can suggest they Google ‘steam weeding’ or ‘killing weeds with hot water’. Thx for a great post.

    1. Valerie, I haven’t used it on the lawn, as I think it would damage the grass. However, it does an excellent job killing the weeds in the gaps of sidewalks, patios and driveways.

  13. Hi thanks for the idea, but i was just wondering is it harmful to the plants close the weeds, the plants that you want to kerp

    1. Bob, I primarily use this method on weeds in the cracks of the patio or sidewalk blocks, so there are no adjacent plants. I also place a large piece of cardboard at the end of the gap, if it is close to the garden bed.

  14. Great tip! I’m glad to see how well they worked with the pineapple weed. I’m having a problem with them this season and even the toxic herbicides don’t seem to work (they are especially waxy plants…) Thanks, will definitely try!

  15. Does this mean that the weeds will permanently disappear, or is this a temporary solution. Currently I use the detergents that I buy from my local shop, but it’s an expensive exercise because I find that I must do this almost every two/three weeks.

    1. Edward, it gets rid of the annual weeds very well, and they rarely need another application. It seems to kill their seeds too, as I don’t get many germinating again that season. With some established perennial weeds, I need to do another boiling water treatment on those spots a few weeks later, then almost all are gone for the season. After a few years now, there are less to treat the next year. I have a short growing season, and the winter snow puts a stop to them for part of the year. It’s possible that in a longer season, it would need more applications.

  16. What would you suggest for evil quackgrass? We are removing our lawn next year and need to kill off the existing quackgrass in the lawn. Do you have any suggestions? I have cut my lawn size down to about half and made large sweeping garden beds against the foundation. I put down multiple layers of newspaper and then covered it with mulch in the flower beds. We had good success with this in our other front flower bed. The problem is the quack grass keeps creeping back in from the lawn and the lawn really needs to be replaced anyway as it is infested with other weeds and very compacted. Our clay soil in Edmonton helps with that. :) I have tried to find a chemical free way to replace the lawn but I may have to resort to Round-up and start fresh. I really don’t want to as my yard is chemical-free so far. Any ideas would be appreciated.


    1. Carrie, I don’t have a really good solution for it. Like you, I’ve decreased my lawn by adding more gardening beds, since there are always more plants to try. :)

      To keep the lawn out of my garden, I keep a small trench about 5 to 8 cm (2 to 3 inch) deep and wide at the front edge. It is straight down on the lawn side, and sloped on the garden side. It makes a nice clean visual edge between the two, and sometimes I put mulch in it. About once a year, I go around and sharpen the front edge by cutting down. I use an ice breaker. [Can you tell I’m from Edmonton? :)] However there are other tools that would do the job too.

  17. I am doing this project in class where I have to study what are the most effective types of pesticides on different types. What types of weed were on your sidewalk/path if you don’t mind me asking.

    1. The boiling water works quickly with annual weeds, and some perennial or established weeds might need a repeat application. Some of the weeds were pineapple weed, Centaurea (knapweed), Sonchus (sow thistle), Matricaria (scentless chamomile), and dandelion.

  18. I have a question about the boiling hot water and poison ivy? Will this trick work with poison ivy? What about poison ivy around a large tree? I’m afraid of using this method where I need to rid of the worst weed problem I have. Let me know and thank you very much.

    1. Teresa, I haven’t tried it on poison ivy, but I tend to think that if the poison ivy is established, it probably won’t work. It would be worth trying it though, to see how effective it is. Let me know how it goes for you, since I’m sure other gardeners would be interested to know, too.

  19. Yes! the boiling water idea seems to work great – hoping it will also kill the many ants who live in the cracks – what do you think !

    1. Helen, I really only paid attention to the weeds on the cracks. I have noticed that there are fewer weeds in succeeding years after using the boiling water, though.

  20. I’ve been using this method to kill weeds in our lawn. It takes a long time to boil the water and then kill a few at a time but as you’ve described and shown, it works wonderfully and the benefits include immediate gratification (die evil weed!). I think I will employ a larger pot on a propane stove to get more production.

    1. Mark, I keep a few pots boiling and have two coffee carafes to carry it. The boiling water is a remarkably effective and quick method to kill weeds.

  21. Will extremely hot water from the tap work or does it have to be boiling? My patio is made of pavers and it is overrun. I’m seriously thinking of smuggling in Killex from the States. lol.

    1. David, I’ve only tried it with boiling water, although that would be an interesting experiment to see how hot the water has to be. However, I would hate to end up just giving them a refreshing watering.

  22. At what tempeture would the water have to be to kill the weeds. I have a too large a yard to boil water all day, but I was thinking of using my garden hose which sits out in the hot sun all day, whose exposure causes the water to come out scalding hot for the about the first minute before the cold water comes through the pipes. I don’t know what the tempeture is but I’m sure it’s not boiling point (212 degrees), but it is hot enough to cause a first degree burn to skin if exposed to it too long.

    1. Steve, I’ve only tried it with boiling water, which is very effective. By the time I pour the boiling water into the carafe and take it outside, the temperature would be below boiling, but I haven’t measured it. It would be an interesting experiment to try it with different water temperatures and test for the effectiveness.

  23. By the way… Found out about the boiling water trick from an episode of “Extreme Cheapskates” on TLC where a guy would use boiling water instead of buying weed killer spray. Then I googled boiling water kills weeds and found you. Interesting show by the way, especially the episode where a woman eats out of a dumpster and refuses to buy toilet paper.

  24. Hi. I have a big weed problem in the back corner of my backyard. I also have a large tree that is surrounded by this weed problem & a giant willow tree at the edge of this weed problem. The weed roots are deep (the weeds have made it to a few feet high) so I would have to go a bit extreme & this method seems the safest for my 2 children, but would boiling water kill a big tree? ( the willow is at least 70 years old & the other tree may be around 50-70 it’s hard to tell)

    1. Laura, I usually use it for weeds in cracks between pavement. Willow roots can go deep, but they’ll have shallow feeder roots, too. Overall, I don’t think it would hurt the willow, but I understand not wanting to risk hurting the tree. Another method would be to temporarily cover the weeds with a large piece of plastic that blocks the light.

  25. Thanks for providing the pix. I had heard about this method before, but the pix prove the point.

    I too am in zone 3 – Northwestern NB, and we too get long winters with -40 temps.

    May I suggest that once the weeds are removed, one plant creeping thyme in the cracks. I have one plant I grew from a 2-in. thread obtained from someone I know. It has now grown enough for me to take additional threads to position in between flat stones in the paths in between my flower beds. Creeping thyme is VERY hardy, and also flowers beautifully. All there is to do is to take a 2 to 4 in. thread and bury it superficially in one of the cracks, cover it with sand or soil, water it a bit, and wait. The thyme grows soooo dense that hardly nothing can grow through it.

    Happy gardening to all !

    PS – If you have Red Lily Bugs eating out your Fritillaria and lilies, simply dust the entire plants with wood ash from your fireplace. Wait half an hour, then rinse off. Some bugs may show up after a few days, only repeat the treatment. I had to spray one plant 3 x this years, the others only 2 x, and I’m completely rid of them.

    1. Denys, you’re welcome; it’s an easy and effective method, and environmentally friendly.

      Thanks for the suggestion about using thyme between the cracks, and the wood ash tip.

  26. I have a large patio area with the lots of weeds between the interlock stones. Would attaching a hose to the hot water from the laundry room be just as effective? Keeping in mind that the water won’t be at boiling temperature?

    1. Katz, is it hot water that you could wash your hands in? That doesn’t sound hot enough, and you don’t want to end up giving them a refreshing drink. You could try it on a small area first to see how it goes.

  27. Thanks for your response.
    The temperature of the water will actually be the hottest that comes out of the faucett. It will be more hotter than the hands can bear. I’ll take your advise and try a small area.

  28. I add salt to the boiling water for weeds in gaps of the cement. It makes the soil unliveable for anymore weeds to sprout. Wouldn’t use it in the yard though as it is non selective and will kill everything.

  29. I tried hot water boiled by my coffee machine and I don’t think it’s as effective as boiling water from the stove.

  30. That’s what I’ve been doing as well. I tried hot water from the tap, hot water from the coffee machine, and boiled eater on the stove. Hottest and most effective was the stove of course so I’ll keep on doing that.

  31. I have a rocked area that has weeds growing in it….tough to pull out…there are also trees in this rocked area… Will it hurt the surrounding roots of the trees?

    1. Thefamilymanager, it probably won’t, but you might want to do one section at a time, rather than the whole area at once. When digging a new bed around a tree, I try not to dig all around the tree at once, to avoid disturbing it too much.

  32. Hello all readers. What you have written sounds very useful for my garden too. My garden enemy is bind weed. The one with the large white flowers that tries to strangle everything on its route. i read somewhere that it can grow 40cm in one day. This weed is in my garden not in the pavement so I would have to try specific bits as the little twerps surface. I am worried about something though and i wondered if you have seen this. If I lift anything that has been on my paving area for any amount of time even say 1 week there are always earth worms on top of the paving but under the other object. this means that there are many worms near the soil surface under my paving. Would the boiling water not terrify them? I am a bio dynamic bee keeper in The Netherlands so I try to see the pollen and nectar value in all growing plants but sometimes they grow too far onto public areas or are just really in the wrong place. I also have a problem with wild strawberry plants that throw creeping stalks this plant is always trying to take over my lawn. It will not stay behind the border wall we placed between garden beds and grass. I think it is going to get the hot bath treatment too. Thank you for sharing this information

  33. when spot treating weeds with boiling water in your lawn, will the grass died as well. I have centipedes grass and don’t want it die.

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