How to fumigate garden soil? (Explained for Beginners)

by Alex Kountry
Updated on

Fumigation has to do with controlling pest that is harmful to your crops in the soil.

The process involves adding pesticides or soil fumigants to the soil,

These fumigants are always in the form of gasses, it is designed solely for getting rid of the pest in the soil, but if not properly handled can also cause injury to people around where the fumigation taking place and also the person apply g them.

Fumigating has to do with applying special chemicals in the form of gases into the soil to kill off any pests in the soil.

Soil fumigation when applied to soil form gas to control pests that live in the soil, nematodes, bacteria, weeds, insects, fungi, etc, are some of the things that soil fumigation will control.

How Do You Fumigate Garden Soil?

How to fumigate garden soil

Fumigation, most especially that of soils, is a little complex to undertake, it should not be used by individuals that are not trained and don’t know what they are doing as fumigants can be hazardous.

On the other hand, if it is applied by properly trained individuals they are safe and effective against pests in the soil.

It is wise to bring in professionals to come to fumigate for you, there are some regions where only professionals can fumigate legally.

Fumigation is affected by lots of other factors like soil, soil moisture level, temperature, and even the content of their organic matter.

The first step in fumigation is to properly prepare your soil to be fumigated, next determine and pick up the type of Fumigant that will be useful to your soil and how deep to apply this,

this process is determined by the pest to be controlled, the feature of the soil and dosage of the Fumigant.

Here is an article I wrote on using garden soil in growing bags

What Is a Soil Fumigant?

Soil Fumigant is a pesticide that when applied to the soil turns gaseous and it is used to control pests living within the soil.

Soil Fumigation involves using pesticides that convert to a volatile gas, the gas then diffuses through the pores found in the soil and controls all soil-borne pests and diseases.

Soil fumigant is used globally on a wide variety of annual and perennial crops, they can either be used alone or used in combination with other pesticides to get rid of pests invading the soil.

After fumigation, the gas must dissipate from the soil before you can consider seeding or transplanting so it does not cause injury to your crops.

Soil Fumigants are used to protect investment in crops where pest activities are much, they are used commonly in high-value cropping systems where crops on a grow would be almost impossible without using fumigants because of the high rate of pest infestation.

Different Fumigants have different effects on the control of pests, some are just developed for pests while others are broad-spectrum and would kill most if not all soil organisms.

What are The Advantages of Garden Soil Fumigation?

Having healthy soil is important to the health of your crops

Some of the advantages of Garden Soil Fumigation are listed below:

  • Reduce harmful pathogens in the soil and rebalance the soil microbe population that are beneficial to the soil
  • Helps check the spread of unwanted pests in the soil
  • Fumigation helps keep the soil healthier and enables good growth of your crops
  • They are used in getting rid of hard to reach and difficult to control pest
  • Makes it possible for consumers to be able to purchase fresh fruits and high-quality crops
  • Increased crop management flexibility makes it possible for you not to wait long periods for crop rotational intervals.

How Do You Make a Fumigation Solution?

To make a Fumigation solution, consider going for low-pressure compounds like ethylene dibromide and Ethylene chloride as they diffuse more slowly.

Some common fumigants used in treating soil include methyl bromide, dichloropropane, propylene oxide, etc.

Since fumigation is to be done just by professionals and for the fact that it is harmful even to humans if it is not handled carefully,

it is not recommended to learn how to make fumigation solutions at home, you can however make pest control insecticides that are fairly safe to use around humans.

You can however make a solution of hydrogen peroxide to use as a fumigant to get rid of pests in your soil.

Hydrogen peroxides will not only eliminate pests from your soil, but they can also be used for disinfection, and seed starting among other things.

You can purchase the hydrogen peroxide compound from pharmacies, take safety measures by using goggles, rubber gloves, long sleeves, and boots when using it, hydrogen cause skin irritation,

if you are getting a 35% solution of hydrogen peroxide, ensure you dilute it with water to make a 1:10 solution, endure you handle the higher concentration with care, use a well-ventilated area and store in a cool dry place out of direct sunlight.

Also check out this article I wrote on mixing perlite with garden soil

What Is The Best Chemical for Fumigation?

The best chemical for Fumigation is formaldehyde vapor,

we have got chemicals like methyl bromide before its use got restricted because it depletes the ozone layer, other chemicals include the 1,3 dichloropropane, dazomet, chloropicrin, hydrogen cyanide, phosphine, sulfuryl fluoride, DBCP, Iodoform, etc.

What to Add to Garden Soil to Make it Better?

Soil is the essential piece of the puzzle you need to get right if you want to grow healthy and productive crops.

Like I have been saying, healthy soil is a healthy crop.

Some things to add to your garden soil to make it better include:

  • Compost: composite adds both nutrients and organic matter to the soil while at the same helping the soil to retain moisture, and the good news is, apart from purchasing it, you can make your ost at home, you can make use of disposable things from your kitchen like eggshells and coffee grounds. Compost boost both plant growth and health impressively.
  • You can consider using aged or composted manure in your soil will help in adding nutrients, rich organic matter, and most importantly add microbial action, some manures you can add to the soil are chicken manure, it is high in nitrogen which is good for your plants, cow manure, it is all-purpose manure you can add to your soil, etc.
  • Cover crops are another way you can add nutrients to your soil, they also improve drainage, aeration, and smothering of unwanted plants.

How Do You Refurbish Soil?

Soil refurbishing is a very important aspect of maintaining good properties and ensuring you have healthy soil.

Soil refurbishing will save you money as you would not need to purchase potting soil for your grow bag, but you can make use of your old soil after having it refurbished.

Some steps to refurbishing your oil include:

  • Remove all dead and old plant matters like  twigs and leaves from the soil, pull out any dead weeds, plants, and any other garden debris
  • Make a layer of about 3 to 4 inches by fluffing and tilling the soil, loosen up the soil by breaking up any large clods you may come across, sprinkle some water on the soil and leave it under the sun for at least a week
  • When leaving it sunlight for a week, on the second day, ensure you cover the soil with a polythene sheet so that weeds do not end up growing in the soil
  • Check if the soil is dry enough for you to move on to the next step of refurbishing it, one way to consider the dryness is to pick some of the sand, squeeze it into a ball then flip it with a finger, if it is just makes a small dent and retains its shape, the soil is not yet dry but if it just scatters then it is ready to move on to the next shape.
  • Add nutrients to the soil by mixing it with fresh compost like decomposed cow dung powder for instance etc. The percentage of the compost should be at least 30% or 1:1
  • To combat fungus and other pathogens that may likely be harmful to your soil, you can organically make use of 10% Neem leaves to aid you in that.


Fumigation is important if you want to maintain soil health and ensure pests do not compete with your plants for nutrients or end up eating up your plant roots.

Fumigation on soil releases gasses into the soil that inhibits air from going in, making the pest in the soil suffocate and die, when fumigating it is important to take the necessary measure so you do not end up hurting yourself.

Soil refurbishing is also important because it helps in rejuvenating old soil and making it to be reusable.

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About the author

Alex Kountry

Alex Kountry is the founder of HayFarmGuy and has been a backyard farmer for over 10 years. Since then he has decided to write helpful articles that will help you become a better backyard farmer and know what to do. He also loves to play tennis and read books


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