Does Hot Water Kill Weeds?
Does Hot Water Kill Weeds?
If you read this blog, you know I am a big fan of finding ways to kill weeds naturally without chemicals. My favorite non-toxic all-natural weed killer hack is using vinegar on my patio every summer. Then one really hot day as I went to water my garden, the water coming out of the hose was very hot from sitting in the sun. I worried, oh, I’d better let the hot water run out first so I don’t kill my plants. Then I thought…huh, hot water might kill plants. Maybe I could kill weeds with plain old hot water. Why didn’t I ever think of this? I decided to try it out.
I chose some cracks in my driveway that had gotten pretty full of weeds. I decided for this test, the hotter the water, the better, so I put a full tea kettle on to boil. Once the water was piping hot, I went out and doused the cracks really well. I checked back in a couple days and here are the results:
As you can see, those weeds are quite dead. So it worked pretty well. I will say that I have used boiling hot water a few times on driveway cracks since I originally created this post, and the results have been more hit or miss. I wouldn’t think anything could survive boiling hot water, but sometimes I find that, surprisingly, some weeds don’t get killed with the first application. You may have to do it more than once.
I would not use this technique on any weeds that are anywhere near other plants, but for sidewalk and driveway cracks, patios and so on, it’s fine. If you had a really large area, it might be tedious to have to keep heating kettles of water and going back and forth, but in a pinch, it’s a decent weed-killing option.
Update: I recently decided to do a more thorough test of different natural weed killers, comparing salt, hot water and vinegar. Click the photo for results of that test.
