How to Make Homemade Insecticidal Soap for Cannabis?

Created by
Added 22 November 2022

We love cannabis plants for one reason — the flavorful (and magical) buds that grow on them. But many other organisms in the environment love cannabis for other reasons. Out of all, perhaps the most dangerous are pests or insects. 

Insects like aphids, whiteflies, and spider mites love cannabis as a host — they feed on the cannabis plant in an uncontrolled manner, and most pest species can multiply within days. If untreated, these harmful pests can stunt your plant’s growth, affect the yield, and even kill the plant.

This is why you must keep these pests out of your cannabis garden. But what happens if one of them makes way and starts a family on your Purple Haze plant? It’s time to pick up arms and eliminate them. And one of the best and safest ways to eliminate pests from cannabis is by using insecticidal soap. Here is how you can prepare it at home. 

What is an Insecticidal Soap for Cannabis?

What is an Insecticidal Soap for Cannabis?

In the word “insecticide”, the suffix, “cidal” refers to killing, so an insecticide is any solution that can kill pests or insects. However, not all insecticides are the same — some use oils as their base ingredient while others use neem. Here, an insecticidal soap uses soap as its active ingredient that kills the insects. 

Insecticidal soaps are an effective way to eliminate pests from your cannabis garden without having to rely on harsh chemicals or pesticides that may be harmful to your plant and the environment. 

Why are chemical pesticides harmful? For various reasons. Some contain toxic chemicals that can affect the soil ecology of your garden, and others may contain potent compounds that can be too much for your plant to handle. Additionally, chemical pesticides during the flowering stage can leave a nasty aftertaste on the buds and even make them harsh to smoke. 

What’s more, some of these pesticides take it a step further and can affect your health. Although not all chemical pesticides are harmful, growers tend to prefer natural or organic alternatives to be on the safe side.

And insecticidal soaps are a great alternative — they are safe for plants and the environment and easy to prepare, too! 

Here are some of the common pests insecticidal soaps can work against:

  • Spider mites — these common cannabis pests can wreak havoc on your plant by building cobweb-like strands and a spider mite infection can make the leaves turn yellow, wilt, or shed
  • Thrips — this is another common pest that likes to feed on young tissues of the cannabis plant, which often leads to distorted growth 
  • Aphids — this quick-multiplying bug likes to feed on the cannabis plant’s sap, stealing crucial nutrients from the plant
  • Mealybugs — like aphids, even these bugs feed on the sap, which can lead to various growth problems in your cannabis plant

These are the four most common pests, but insecticidal soaps are effective against many other pests that may infest your cannabis garden. 

How do Insecticidal Soaps Work?

How do Insecticidal Soaps Work?

If you use a microscope to look at how insecticidal soaps (or any pesticide for that matter) work, you’ll see how brutal the process is. However, it is crucial to save your cannabis plant from failing due to pest infestations. 

Essentially, insecticidal soaps work in two ways — they suffocate the pests and dehydrate them.

When you apply insecticidal soap to your cannabis, the soap affects the insects’ ability to intake oxygen by disrupting their cell membranes. Once the cell membranes are interrupted, their bodies cannot control the movement of compounds efficiently.

On the other hand, insecticidal soaps also target the waxy coat of the insects, which is produced by the cuticle. This outer coat protects the insects and acts as an anchor point for their muscles, and it works by locking moisture within to keep the insects hydrated. When you apply an insecticidal soap, the coating quickly perishes, leading to moisture loss within the insects’ bodies, leading to dehydration and death. 

How to Make Insecticidal Soap for Cannabis at Home?

If you suspect a pest infestation on your cannabis plant, a DIY insecticidal soap will work if need to act quickly. Fortunately, preparing your homemade insecticidal soap isn’t that difficult — as long as you use the right ingredients. Here is a brief guide on how to make insecticidal soap for cannabis at home.

Gather the Supplies 

Gather the supplies

  1. 5-liter plastic bottle
  2. Stirring stick
  3. Spray bottle
  4. 2 ½ tablespoons of pure, organic liquid soap without any artificial colors or fragrances (like castile soap)
  5. 2 ½ tablespoons of vegetable oil 
  6. Water 

What makes insecticidal soap better than chemical pesticides is that it does not contain any harmful compounds that can pollute the local environment or affect your buds’ flavor profile. So, when choosing liquid soap, you need to ensure you pick the right one.

Make sure the liquid soap you choose is organic and natural. For example, you can use Castile soap or other similar soaps that contain ingredients like shea butter, aloe vera, salt, vegetable oils, and essential oils. 

Follow These Steps to Make Homemade Insecticide Soap

1. Add 4 liters of water to the plastic bottle and mix in the soap and vegetable oil.

Mix water, soap and vegetable oil

2. Use the stirring stick to mix the liquids properly.

Mix everything

3. Cap the bottle and shake it vigorously for a couple of minutes.


4. Pour the solution into the spray bottle.

Pour solution in spray bottle

5. Store the rest of the solution in a cool, dry area in your home.

Store the solution

How to Use Homemade Insecticidal Soap for Cannabis?

How to Use Homemade Insecticidal Soap for Cannabis?

Now that you have your homemade insecticidal soap for cannabis ready, the next step is to use it. But it’s not as simple as bathing your plant in this soap any time you spot a bud. There are a few precautions you need to follow. Follow these tips on using your homemade insecticidal soap:

  1. Do a patch test — spray the solution in a part of the plant and wait for a few hours to see if the plant reacts negatively to the spray. If you notice wilting or brown spotting, stop using insecticidal soap or dilute the solution even more.
  2. Insecticidal soaps have a short efficacy window, so you need to spray them directly on the bugs.
  3. Typically, these nasty pests like to hide under the leaves, so check there first. 
  4. Avoid spraying your entire plant with this solution. 
  5. It is recommended that you apply this soap spray during the evenings. Applying it during daylight can cause sunburn on the plant. In addition, beneficial insects are less active during the evening and you don’t want to harm your little buddies. 
  6. Check the next day’s forecast. If it’s going to be hot and sunny, you should rinse your plant the next morning with clean water to prevent sunburn. 
  7. Re-spray the solution every few days until the problem is completely solved and all the pests are eliminated. 

Fortunately, this insecticidal soap is not toxic at all, so you can use it liberally without worrying about affecting the buds’ flavor profile. However, it is still recommended to not spray the soap directly on the buds to keep them safe.

What CanYou Add to the Insecticidal Soap to Make it More Effective?

What Can you Add to the Insecticidal Soap to Make it More Effective?

Even after using your homemade insecticidal soap on your cannabis plant multiple times, the pests may be persistent enough to survive the entire ordeal. That’s normal. Some pest species are more resilient than others. 

In that case, you can try mixing other products with your insecticidal soap, too, such as the following.

  • Neem Oil

Perhaps the most popular natural insecticide and fungicide for cannabis is neem oil. This amazing compound, derived from neem, contains various compounds that can kill pests and affect their feeding abilities. Additionally, neem oil also contains azadirachtin, which interrupts their hormone systems, preventing them from growing and laying eggs. 

Neem oil can also help you get rid of powdery mildew on your cannabis plant, which is also quite common in humid regions.  

  • Oil-Based Insecticides

Oil-based insecticides use oils as their primary ingredients, ranging from canola oil, soybean oil, and cottonseed oil to essential oils like eucalyptus, lemon, cinnamon, and rosemary. 

All you have to do is dilute the oil of your choice in water and spray them on your plant. They are safe to use on your cannabis plants and easy to prepare but note that applying them directly to the buds can affect the flavor profile. 

  • Chilli- or Garlic-Based Insecticides

On the other hand, you can use chili- or garlic-based insecticides, but these are best used to deter pests, not kill them. This is because both chili and garlic are natural bug repellents, not bug killers. 

You can also use tomato leaves. Tomato is a member of the nightshade plant family, which contains alkaloids that are harmful to pests. So, even tomato leaves can help you deter pests from entering your garden. 

Summary: How to Make Homemade Insecticidal Soap for Cannabis?

Insects are a nuisance unless they are the beneficial kind. Beneficial insects are our friends. But other insects that feed on your cannabis plant must be eliminated. And your homemade insecticide soap can help you do that. 

Use the steps listed above to eliminate pests from your garden. But if the problem persists, don’t hesitate to use some other methods.

Lastly, if you are growing outdoors, you need to accept the fact that there will always be a few bugs lingering on your cannabis plant. That’s natural. But if the number increases, you need to take countermeasures. 


Be the first to comment it