How To Kill Weeds in Sidewalk Cracks with A Blow Torch

If you’re looking for an easy way to kill weeds in sidewalk cracks without using chemicals, using a blow torch (also called a weed torch) is one of the fastest and most effective methods. Instead of pulling stubborn weeds that keep growing back or spraying harsh herbicides, you can use heat to destroy the weed down to the root. In this guide, I’ll show you exactly how to kill weeds in driveway and sidewalk cracks with a torch, plus tips to do it safely and effectively.

Do weeds take over the cracks in your sidewalk or driveway every single year? Same here.

No matter how hard I try, pulling them out never really works—the roots stay behind, and they just keep coming back.

Instead of reaching for harsh chemicals, I’ve found a much easier (and honestly kind of satisfying) solution—using a blow torch to scorch them right at the root.

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Let me show you exactly how I do it!

My husband recently picked up a small butane blow torch for projects around the house—things like loosening stuck bolts. But if I’m being honest, I think he and the boys have gotten just as much enjoyment out of using it to start fires in our Breeo smokeless fire pit 😂

One summer day, while I was weed whacking along our never-ending sidewalk, I hit my breaking point. The cracks leading up to our front door were completely taken over with weeds. And every time I weed whacked, it just made things worse—spreading clippings and seeds right into my flower beds.

That’s when I had a genius idea…
Why not just torch them?

I walked straight into the garage, grabbed the torch, and got to work burning those weeds right out of the cracks.

And honestly? It worked.

This method has become my go-to for keeping weeds under control without using harsh chemicals that can soak into the soil and affect surrounding plants (and animals). Plus, pulling weeds from cracks is nearly impossible—the roots stay stuck deep below the surface—so this just felt like a win all around.

Before You Torch Your Weeds

Before you get started, take a few minutes to prep the area safely:

• Make sure there are no nearby electrical lines, irrigation, or anything flammable
• Clear away mulch, dry leaves, or debris from the sidewalk edges
• Keep a watering can or hose nearby just in case
• To cut down on the amount of butane you use, pluck the weeds first

How to Kill Weeds with a Blow Torch

Here’s exactly how I do it 👇 Watch how quickly the weeds wilt when the heat hits them:

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Here’s exactly how I do it:

1. Turn the torch to a heat level you’re comfortable with
2. Hold the flame about 1/2 inch to 1 inches above the weeds
3. Slowly pass the flame over the weeds until they wilt or lightly catch fire
4. You may need to repeat the process for thicker or stubborn weeds
5. Once cooled, use a pointed hand shovel to scrape out the cracks
6. Sweep everything up with a push broom or use a leaf blower to clear debris
7. Pour water over the area to ensure no fire remains

The Aftermath (What to Expect)

While this method works really well, it’s not a permanent fix.

I found that the weeds stayed gone for several weeks, but eventually started creeping back. That said, since we personally choose not to use chemical weed killers in our yard, I’m completely okay with repeating the process.

For me, the extra few minutes it takes to torch the weeds again is absolutely worth avoiding chemicals and keeping our yard a little more natural.

Frequently Asked Questions

Does a blow torch permanently kill weeds?
No, using a blow torch does not permanently kill weeds. It destroys the visible growth and damages the plant, but roots may survive. You will likely need to repeat the process every few weeks.

Is it safe to use a blow torch on weeds in sidewalk cracks?
Yes, but only if proper precautions are taken. Always clear away dry debris, keep water nearby, and avoid using a torch near flammable materials or structures.

Do you have to burn weeds completely to kill them?
No. You don’t need to fully burn weeds to ash. Heating them enough to damage their cells is usually enough to kill them.

Is using a weed torch better than pulling weeds?
In cracks and tight spaces, yes. Pulling weeds often leaves roots behind, while heat can penetrate deeper and prevent quick regrowth.

Can I use a blow torch instead of weed killer?
Yes, a blow torch is a great chemical-free alternative to traditional weed killers, especially for sidewalks, driveways, and gravel areas.