It is much harder to get rid of pests once they have invaded your grow space. As the Dutch philosopher was attributed as saying, “Prevention is better than cure.” It is best to prevent an infestation of your cannabis plants rather than have to deal with the task of getting rid of the pests once they have moved in.

You should be checking on your plants daily. Look for signs of the presence of insects. Do the leaves suddenly have holes or bite marks? Check the stems also. Does the plant show signs of stress? Are the leaves a deep, lush color? Do the leaves look yellowish and dry?

All of these are signs that there is something wrong with your cannabis plant. You should take action immediately. If there is an infestation, you will need to identify what the pest is and take appropriate action to get the situation under control.

Sterilized Soil

In order to follow the advice of prevention is better, we should take a step back and look go to the beginning. You have everything you need to start your grow. You have your seeds, fertilizer, hydration plan, the soil you are going to grow in, etc. Here’s a question for you: what’s in the soil? Are there any eggs waiting to hatch? You can’t know.


This is primarily a problem for indoor growers. Outdoor growers can have pests show up because they are in the outdoors. However, it is good practice to sterilize your soil. You sterilize your soil by heating it. Soil becomes sterilized at 180 – 200 degrees F after 30 minutes.

There are three main ways you can sterilize your soil. Each way will require some equipment and time. All three ways will require a meat or candy thermometer to check the temperature.

Your Oven

If you only have a small amount of soil to sterilize, then your oven should work well enough. You will need soil and something to place it on. Preheat your oven to between 180-200 degrees F and put your soil in. When the soil comes to temperature. Time it for 30 minutes. Let the soil cool down before using.



If you are planting outside, you can use solarization. Solarization is the process of using a clear tarp to trap solar energy in order to raise the temperature of the ground. Using your thermometer as a probe, check the temperature. When it hits the appropriate temperature, time it for 30 minutes. Then remove the tarp and let the soil cool down.



You can steam your soil in order to sterilize it. Steaming your soil will require the purchase of a steamer. Depending upon the amount of soil you wish to sterilize, this equipment can get very expensive. Keep this in mind. Otherwise, the process is pretty easy. Set up your steamer, turn it on, when the temperature hits 180-200 degrees F, let it sit for 30 minutes.

When you finish, move on to the next bit of soil that needs to be sterilized. Let the soil cool. If you have a small amount of soil to steam you can probably get away with using a home steamer and a heavy-duty bag of some sort. Otherwise, you will need to look into more expensive options, up to industrial-sized steamers.

Check out a video on steaming soil.

When you are finished sterilizing your soil, it is important to fertilize it. A lot of the beneficial nutrients that were present in the soil will be “cooked off” and you will need to replace them. Once you have made sure that your fertilizer is distributed throughout the soil, you are ready to plant your cannabis seeds.


The easiest way to get rid of pests on your marijuana plant is to use a pesticide. However, many of these can be dangerous. You will be ingesting this plant, or giving it to someone who will be, and dangerous chemicals should not be considered.

There are organic alternatives that you can use. One that comes to mind is neem oil. Neem oil is derived from the neem plant. If diluted properly neem oil is considered to be safe for use in the garden.  

For more information on using neem, check out or blog post on How to get rid of leaf miners on your cannabis plant.

Companion Plants

Companion plants are plants that you plant alongside your cannabis plant in order to help with soil nutrients or to pull pests away from your cannabis.

Some plants, such as mint have a very strong smell. Many pests are not fond of this smell and will avoid mint. If you place mint in pots around your cannabis plants, it can help to deter the arrival of pests.


Other plants, such as Chrysanthemum, can pull pests away as sacrificial plants. That way the pests will go for the Chrysanthemum instead of the cannabis. As an added bonus, the flowers on the plant can attract predators.

Check out our blog post on Companion Plants to learn more about which plants serve as companion plants, and what they can do.

Predatory Insects

If there is one thing that can be counted on in nature is that there is always a predator. Predatory insects can quickly diminish a population of pests on your cannabis plants.

Some predatory wasps lay their eggs in caterpillars. Other wasps kill leaf miners and lay their eggs near them, providing their young a meal. These insects are highly specialized at hunting down certain pests and killing them. Check out our blog on How to get rid of caterpillars.


Ladybugs, or ladybirds, are very good ant controlling aphids and spider mites. They are also known to eat the larvae of some moths and even some smaller insects. Check out or post on Fighting Spider Mites with Ladybugs

Leaf Hoppers are a pest that can plague your cannabis plants. They suck the sap out of the plant and can do a lot of damage to your cannabis plants. In the spring they can lay up to 6 eggs a day. If you don’t catch them when they have just arrived, it can get out of hand quickly. You may be surprised to discover that Ladybugs can be very useful in controlling leafhoppers. Check out our blog on How to get rid of leafhoppers.

A Few Last Words

We have covered a few pests and how to manage them. Remember to stay vigilant. An infestation is harder to get rid of than it is to prevent. Find out what you are dealing with and how to deal with it.

Remember to Identify a threat, Decide on a course of action, and Act. For more information on growing cannabis and other topics related to it, check out our blog