Using Boiling Water to Kill Weeds: All You Need To Know

People have been using boiling water to kill weeds for centuries. It’s not a new practice.

Unfortunately, it is also not a practical method for large-scale commercial farming. However, boiling water as a weed killer for small backyard gardens is still viable.

It’s called thermal weed control, and its whole point is to destroy plant cellular material with the heat from the hot water [1]. It works because water is one of the most effective energy transfer methods.

And since water naturally flows down into the ground of its own accord, it’s the easiest method for reaching the roots. That, of course, is compared to air, which usually rises first, thus negating some of the heat energy.

Does boiling water kill weeds? Yes, it does. It’s an excellent alternative to Roundup since pure hot water contains no chemicals, and it’s free!

Hot Water for Weed Control

Plants are delicate, which is one reason boiling water works so well. It’s the perfect natural weed killer for small gardens, sidewalks, and between block paving, and it’s entirely non-toxic.

Pouring boiling water on weeds will not harm other plants in the garden or nearby lawn grass, so long as you’re careful about where you apply it.

It also will not affect you if you dress appropriately and handle it cautiously.

Attire

• Long pants
• Long sleeves
• Closed shoes
• Safety gloves

When killing weeds with boiling water, the less exposed skin there is, the better. This will help prevent accidental burns.

Identifying the Weeds

Before you begin, make sure you know what you intend to get rid of, lest you inadvertently eliminate something you want to keep.

Anything the hot water hits by accident, whether a weed or vegetable, will start to wither quickly. This method works best for sidewalks, cracks, between pavers, and the edges of your lawn and garden.

Scalding hot water can also kill bindweed.

The Heating Process

Fill a teakettle with water and set it on the stove to boil. A thermometer might be handy since the water must be over 200 degrees Fahrenheit [2].

Killing the Weeds

Before turning off the stove and taking the kettle outside, wear oven mitts or Kevlar gloves to protect your hands.

Approach the weeds with extra care but as quickly as possible. The water temperature will drop increasingly quickly, so precision is essential.

If you can help it, you won’t want to make frequent and time-consuming trips back and forth to boil more water. Once in place, hold the kettle’s spout so it tips directly onto the weeds.

You can also snip off the weeds’ fronds. This gives the water a more direct path to the root system.

Aim carefully for the roots to avoid damaging anything else. If you’re not careful, the boiling water will kill grass, clover, dandelions, and other plants you want to keep.

Avoiding Splashes

You’re holding a kettle full of potentially dangerous, scalding water designed to destroy weeds in your garden. You may be worried about the heat when pouring the boiling water.

The best way to curb this is to squat or kneel and pour the water down from a low point. Doing so will make it splash far less than if you held it at hip height.

Will Weeds Grow Back?

If you see a stubborn reappearance of weeds thought long dead, reapply the hot water treatment. With each new application, the plants will start getting weaker.

Usually, it only takes about two or three treatments to see permanent results. However, it will be worth it when you don’t have to pull them anymore.

Can You Use Vinegar Instead of Water?

You can use this handy household product instead of water to help control weeds. Read: How to Use Vinegar to Kill Weeds: Basic Guide.

Boil the vinegar and apply or spray it the same way on any stubborn weeds you want to eliminate.

This is a double whammy as it works both ways. The heat from the hot vinegar will sear the exposed portion of the plant, while the acid from the vinegar invades the plant’s internal tissue and finishes the job below the soil.

Just ensure not to overdo it, or you might overwhelm the soil.

Takeaway

Weeds can be a nuisance to the crop world as they multiply rapidly. They steal valuable nutrients from crops and do not look appealing.

Chemical herbicides are popular right now. However, organic choices are becoming even more popular.

So, the “hot water sprayer for weeds” method is now seen as a simple and affordable way to kill weeds naturally.