How to Use Boiling Water to Kill Weeds – Garden Tips 2024

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As more and more people try to avoid using toxic weed killers in their gardens, most of us are constantly exploring safe, effective methods that work. Boiling water is a remedy that many gardeners advocate. But it needs to be used selectively because boiling water will kill just about anything growing in your garden. 

In essence, all you have to do to kill weeds with boiling water is to pour it over the weeds. It’s particularly effective in paved areas where no vegetation is welcome. In garden beds, you need to be very careful not to kill the plants that grow alongside weeds. 

Can boiling water kill weeds?

The answer to the question does boiling water kill weeds is yes, boiling water can kill weeds. But it’s a non-selective way to get rid of weeds and it doesn’t always kill the roots. It depends largely on the weeds you need to kill.

Information published online by the University of California discusses weed management in detail. It includes every possible method of killing weeds, including using boiling water.

Their guidance is that if home gardeners apply hot water they will “achieve a limited amount of weed suppression.” For starters, the water must be hotter than 200 ℉. At sea level, water boils at 212 ℉, so it needs to be at very least close to boiling point. 

The problem, they say, is that the method loses effectiveness because the temperature of the water drops so rapidly once it is removed from the heat source. 

Another important factor is that hot water is generally only effective for killing very small weeds. It also works best for paving or sidewalk joints, in areas that are adjacent to edging materials, and along fence lines.

In small areas, it’s usually more effective to remove weeds by hand or to trim them mechanically. But then you really do need to be very careful. 

When professionals use boiling hot water for weed control, they often use expensive equipment to ensure success. But they are very expensive and anyone using them needs the training to prevent the risk of severe burns. 

Overall though, boiling water weed control is most effective on young annual broadleaf weeds. It can also be used successfully for weed control of perennial weeds that have just started to grow. 

They warn that hot water isn’t very effective for controlling woody plants. And it doesn’t work well for weeds that grow from rhizomes or bulbs. 

How long does it take for boiling water to kill weeds?

It can take two or three applications for weeds to die when you pour boiling water over them. This means it will take anything from a week to a month to kill the weeds in your garden. 

For this remedy to work, you will need to persist. But rather keep pouring boiling water on your weeds than toxic chemicals. 

A hot water weed killer is definitely a better option. It’s also quicker than laboriously pulling them by hand. 

It is good practice to check whether weeds are growing back. If they are, then repeat the kill weeds boiling water process. 

Even if you have to do this multiple times, you’ll find it is worth the effort. 

How to kill weeds using boiling water

The first thing you need to do is boil water. That stands to reason.

You can’t let the water cool down, so you need to act fast. The quicker you can get the water onto the weeds, the hotter it will be, and the more likely it will be to kill them. 

Really, all you need to do is to pour boiling water over the weeds. Make sure that you only target the weeds you want to kill. 

As long as the water is hot enough, it will kill them. As long as there is enough boiling water weeds will die. 

Bend down and pour the water right onto the weeds. It certainly isn’t the same as giving your plants the water they need to survive. 

Other useful and safe tips when using boiling water to kill weeds

The Extension and Outreach department of Iowa State University advises that using boiling water to manage weeds is great as long as other plants aren’t nearby. It acts as a contact herbicide and kills any part of the plant it comes into contact with. 

As they say, it is most effective if you use it on young weeds that have recently emerged. It is also best used where plants grow in cracks or between paving on patios or on sidewalks. 

They suggest using lots of boiling water and to repeat the process 7-10 days later. As they say, one application of boiling water certainly won’t kill deep-rooted weeds. 

Another tip to remember is that you shouldn’t try to use boiling water to kill weeds in the middle of your lush, green lawn. It’s going to kill the grass as well as the weeds. 

While you don’t have to use PPE to kill weeds with boiling water, it’s not a bad idea to wear clothing that’s going to protect you. But you don’t have to do more than wear long pants, a long-sleeved top, and shoes or boots. 

The general idea is to be sure you won’t be splashed by boiling hot water. 


Using boiling water for weed control is a good organic option, as long as you are selective and don’t use it near other plants. Chemical weed control is generally toxic, and while it certainly does work, it also ultimately destroys other elements of the environment. 

Just remember that the simplistic boiling water weeds control method works best on new emerging weeds. Once they become established, it gets more difficult to kill them. 

You also need to remember that the hotter the water, the better. This adds risks, so it is important that only adults use the method. 

Never, ever, ask your children to use boiling water to kill weeds. Rather, get them to pull your weeds out by hand.

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