Can You Sterilize Soil With Boiling Water?

If you have pest infestation in your garden that’s making it nearly impossible for any of your plants to thrive, you may need to start over from scratch. Though you could always get a new bag of soil, there’s another way to help rid your garden of bacteria and unwanted pests. 

You can sterilize soil with boiling water if your plants experience pest problems or recurring infections. This method will kill any microorganisms within your soil, giving you fresh soil. But since doing this will also kill any living plants and roots, it’s best to do tiny batches at a time.

Below, I’ll talk about the scientific process behind boiling water and sterilization and then provide other methods for sterilizing your soil. Additionally, if you want to sterilize your soil for pest control, I’ll review a few tips for avoiding unwanted bugs in your garden. Keep reading.

Can Boiling Water Sterilize the Soil?

Boiling water is essential for sterilizing many things.

We use hot water when we shower to rid ourselves of dirt. Also, we use hot water when we do the laundry. Some people even wash their hands in hot water to ensure their hands are bacteria-free! What about using boiling water to sterilize soil? 

Boiling water can sterilize the soil. Doing so helps eliminate all the microorganisms living within your soil and disrupt their life cycles or larvae hatching bugs. But bear in mind that doing this will also destroy any plant roots. So, don’t pour boiling water directly on plants or roots. 

The term sterilization technically means to free something from bacteria and other living microorganisms. While boiling water and pouring it on your soil will do so, there still might be some bacteria that hang around, depending on how quickly you can get to them with your pot of water.

As discussed below, water well below boiling temperature usually kills most bacteria, but there are still some stingy ones. For pest control, though, boiling water will do the trick. 

Bed bugs are agreeably one of the most treacherous and hard-to-get-rid-of bugs out there. High heat can get rid of bed bugs, and most pest control companies use a heating method to rid your house of them. You might have heard and used this method for simpler pests such as ants. This method, too, is backed by science and entomologists. It’s an effective method for getting rid of fire ants, according to the AgriLife Extension of Texas A&M.

Boiling Water Is Highly Effective in Killing Bacteria

Why is boiling the go-to method for making things cleaner? You might wonder if it has something to do with the boil notices you get when water is contaminated or if it’s the assumption that boiling water kills germs. Both wonderings would be correct.

Technically, when you boil water to kill the bacteria living with it, you’re pasteurizing rather than sterilizing. Sterilization means that all bacteria are destroyed, though boiling water kills most bacteria. In some instances, the most potent bacteria hold on. 

Boiling water is the most effective way to get rid of cryptosporidium—it’s also how stream water is distilled. But in general, when you boil water (or even milk, tea, any liquid), you’re killing viruses, bacteria, protozoa, and pathogens. This method is tried and true and works so well it’s the go-to method for water purification efforts. 

This isn’t just true of liquids, either. There’s a reason that you don’t want your chicken done rare or your pork over medium. Internal food temperatures are vital for killing foodborne pathogens

Simply put, heat kills bacteria. Even a temperature lower than a boil, about 162°F (72.22°C), is enough to kill many bacteria and viruses. The boiling point of water is 212°F (100°C). 

Boiling Water Can Kill Pathogens and Bacteria in Your Soil

Boiling water can get rid of pathogens and bacteria within the water itself, but it can also get rid of tiny and big organisms alike in your garden.

Though its effectiveness in killing bacteria shows us what boiling water can do on a microscale, this idea still works when discussing big bugs. Big bugs, pests, fungi, or any other living organism driving you crazy, just can’t live in hot water. Whether it drowns them out or kills them, boiling water will get rid of them.

The caveat to this is that it’ll also kill all of your good microorganisms, damage any living plants, and kill any roots within your soil that you want to grow. For this reason, most gardening experts suggest only taking a little bit of soil for sterilization at a time, rather than dumping a pot of boiling water over your garden.

You should also remember that though this method will sterilize your soil, it won’t sterilize your plants. If you rid the soil bed of bugs, this doesn’t stop the bug eggs on the plants from thriving. 

Additionally, fungi and infections are fantastic at clinging to plants. Do what you can to save your loved plants, but don’t forget that sterilizing soil won’t save a plant that’s already sick; it just prevents other plants from getting sick. 

How Can I Sterilize Soil?

But is this the only way that sterilization can occur? Or are there other methods to sterilize your garden? 

You can sterilize soil by pouring boiling water over sections of soil, heating it in the oven or microwave, freezing it, or steaming it. Sterilizing your soil will eliminate pests as it interrupts their life cycles and prevents eggs from hatching. You can also remove fungi with this method.

Sterilize Your Soil if There’s Any Infection or Infestation

Some of you may be wondering why in the world someone would want to pour boiling water over their garden or sterilize it in general. Are they afraid of germs? Want a perfect space? Don’t want dirt?

It might be time to sterilize your garden if it’s dealing with an infection or infestation that you just can’t get rid of with traditional methods.

Suppose you’ve tried all the insecticide, dug out the little buggers yourself, or treated your plants. But the fungi or pests won’t stop. Sterilizing could be the solution for you in this case, as “sterilizing” in terms of gardening usually means getting rid of pests and microorganisms. 

It’s worth repeating that I’m talking about sterilizing the soil. Sterilizing plants or roots is a whole other conversation, and the methods discussed below won’t only be ineffective for sterilizing your plants but will likely cause long-term damage to their growth. 

Tips for Sterilizing Your Soil

If the boiling water method isn’t for you—whether that’s because the distance between your garden and kitchen stove is too far, or it just seems too weird—I’ve discussed a few other methods you can try to sterilize your soil below.

Consider Freezing Your Soil  

Freezing is an effective way of stopping mold growth (hence, why you can freeze cheese and meat), disrupting life cycles (why bugs don’t thrive in the winter), and preventing rot (again, cheese).

If you take your soil in batches, place it in a ziplock bag, and freeze it over a few days, it’ll kill any organisms living within your soil.  

Steam the Soil 

Steaming soil is another method of getting rid of unwanted pests, but it’ll take a little more time. You’ll have to put your soil in batches above a pot of boiling water, which can be done quickly with a baker’s drip rack and a pan. It’s a messy option, but an option nonetheless.

Consider the Microwave or Oven Method

A less messy but equally strange method for sterilizing your soil is using the heat concept above but without water. 

You can place batches of your soil in an oven or microwave to kill microorganisms within your soil. Just be sure not to overdo it because baking your soil will make it nearly impossible for any plants to grow in.

If possible, use a baking thermometer and check to make sure it remains under 180°F (82.22°C). Anything higher will damage the soil. 

Other Strategies for Getting Rid of Pests

If sterilization doesn’t seem to be your cup of tea (get it…boiling water, a cup of tea?), don’t worry; there are also tons of other ways to get rid of pests in your garden.

Use High-Quality Soil and Plants Only

For one, you can follow farmers’ lead, who probably hate pests more than anyone. If a crop is infested with a pest, it usually spreads quickly, destroying a source of food and income. Farmers constantly breed new crops that are more resistant to bugs.

Prevention is one of the best strategies for insect infestations, and you can do this by ensuring you have high-quality soil and high-quality plants

Make Sure Your Plants Are Free From Pests When You Get Them

You should also check your plants whenever you purchase them or bring them in. Scan them to ensure they don’t have pests already on them before you buy them, and double-check them if you ever bring them outside for more sun before bringing them near your other houseplants. 

Consider Methods That Prevent Pests From Thriving

Pest control is pretty straightforward after the fact. Insecticides and pesticides may be the route to go if you need some extra support.

Additionally, though this method doesn’t use the heat principle, water can still help eliminate bugs. Using a heavy stream of water can knock them right off of your plants for bigger bugs. 

Keeping your greenhouse or garden area clean is another big help to reduce pests. 


Boiling water does sterilize your soil by killing all the microorganisms and bugs that live within it. Just be cautious about pouring boiling water all over your garden because it can also harm plants and roots. It’s suggested that you do your garden in small batches to sterilize it if you want to use the boiling method. 

You can also use the steam, oven, or freezing methods to sterilize your soil. Additionally, the best way to stop infestations is to prevent them, to begin with, so do what you can to protect

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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