How to keep bugs off weed plants: Marijuana pest control techniques

Reading time: ± 21 minutes

Marijuana pest control is something gardeners have had to deal with for centuries. 

Whether they are birds, insects, mammals, or even other humans, cultivated plants seem to have a target on their backs.

While humans don’t really eat raw cannabis, some pests certainly seem to like the taste. If left unchecked, an infestation can end up ruining your crop.

At the same time, using harsh chemical products to repel the pests can be harmful to you later on.

To avoid all that, we have compiled a list of some safe and effective repellents (and other safety precautions) to guide you on how to keep bugs off your weed plants.

Don’t want to read? Watch the video!

Use sterilized soil and fertilizer

The problem with unsterilized soil is that it can contain the eggs or even larvae of some common marijuana pests.

If you grow your marijuana in that soil, you will be in for a rude surprise when those eggs hatch or those larvae start to grow up.

sterilized soil cannabis
Use sterilized soil for growing

This is particularly bad for indoor growers because there are no natural predators inside your house.

It’s very easy to sterilize your own soil. The only thing you have to do is cook your soil in the oven to reach an internal temperature of around 160-180F. This will kill all molds, pests, weeds, and seeds.

Depending on the amount of soil you’re sterilizing it will take 30 to 45 minutes to reach 180F.

Do not exceed temperatures of 190F because nothing good can come of this.

Grab our complete fertilizer set to add to your sterilized soil to keep pests’ eggs at bay, and if you haven’t decided which marijuana seeds to grow, visit my seed shop now.

Marijuana Fertilizer

Buy marijuana fertilizer

  • Nutrients from seedling to harvest
  • Maximize your yield
  • Enough nutrients for at least 5 plants
  • Discounted combination deal

Check the soil cooking tutorial by Monad on

For large amounts of soil use 2,5 table spoon of 3% peroxide per gallon of soil. Don’t forget to use fertilizers when you’ve sterilized your soil.

Grow companion plants

Interspersing the marijuana garden with a few naturally repellent plants is certainly a good way to keep the predators away.

companion plants growing with marijuana
Use companion plants while growing

Although the THC that marijuana produces acts as a natural repellent in its own right, it is often not strong enough to repel all plants (especially in the early stages of life).

Download my free Grow Bible for more tips on how to get rid of pests on your marijuana plants.

Grow Bible

marijuana grow bible
  • Grow with my Quick Start Guide
  • Discover secrets to Big Yields
  • Avoid common grow mistakes

    Particularly pungent plants like geraniums and marigolds will keep many leaf-eating insects and worms at bay.

    You can even plant some onions to ward off bigger pests like deer or rabbits.

    Here are some more companion plants your weed will love:


    This garden favorite has a strong scent that is perfect for keeping away thrips, beetles, aphids and flies.

    Growing Basil with marijuana plant
    A basil plant

    Some growers even claim that it can increase oil production and flavor.

    Regardless of whether that claim is true, having some extra basil around is not a bad idea.


    Worried about a nitrogen deficiency? Planting beans may be your remedy.

    Growing beans with marijuana plant
    Beans Seedlings

    When beans are growing, they absorb nitrogen from the air and deposit it as nitrites into the soil. Marijuana plants thrive on these nitrites.

    With beans around, they grow stronger and are actively protected from a slow death due to nitrogen deficiency.


    Garlic is a popular companion because it protects against pests and molds. It is a natural fungicide that protects marijuana plants from deadly diseases.

    Growing garlic with marijuana plant

    If not planted next to your plants, it can also be used in spray form as a spot treatment.


    Marigolds are what many growers call a ‘beautiful distraction.’ When marijuana and marigolds are planted together, cannabis-loving animals opt for the marigold.

    Growing Marigolds with marijuana plant

    It’s so strong that you could create a virtual fence of protection by planting marigolds around your plants.


    Mint is a wonderful companion plant because of its odor. Many garden pests hate the smell of mint and avoid going near it.

    It also masks the smell of freshly blooming marijuana, keeping your grow area a bit more private. 

    mint and marijuana

    Use mint with caution, however. Once planted, it tends to have a mind of its own and may overrun your garden; so, plant mint in a pot instead of in the ground.


    Chili peppers are a wonderful way to keep away large pests such as deer, mice, and rabbits.

    protect cannabis with pepper plants
    Pepper plant

    The chili pepper plant also has a root system that gives off a chemical that protects your cannabis plants from rot.

    These plants are especially useful in areas with poor drainage or excess rainfall.

    Use natural predators

    Of course, if you’re growing marijuana outdoors, you can make use of a few pest predators.

    Ladybugs are notoriously beneficial to have around your outdoor marijuana plants because they love to prey on larvae and other potential pests.

    You can buy life ladybugs at this website for around $5 per 1000.

    You should also encourage birds to nest in the area because they often like to snack on some pernicious marijuana pests.

    Put out some birdhouses or a bird feeder to get birds to come around.

    Just make sure that they stay away while the seeds are germinating because many birds do enjoy the taste of marijuana seeds.

    Use urine of pest’s enemies

    This might sound like a joke, but it actually works and it’s actually feasible.

    Many mammals like deer have a keen sense of smell and if they detect a hint of bear or puma urine, they will want to stay as far away from your marijuana plants as possible.

    Available at

    Predator urine to protect your marijuana plants
    Predator urine to protect your cannabis plants

    That’s because they won’t want to enter territory that a much larger predator has been roaming around in.

    The same is true for rabbits and fox urine. You can buy these scents at many sporting goods or outdoor shops.

    Build a fence

    If bigger animals are a problem and the scent of their enemies doesn’t deter them, then you might need to try building a fence around your plants.

    Fence to protect marijuana plants from animals
    Fence to protect marijuana

    Obviously, many marijuana growers don’t have this luxury and it’s really only something that people growing on private land can do. 

    Here’s a link with tips on how to build your fence to protect your marijuana.

    Create a repellent force field

    With a permethrin-based repellent, you can keep insects away from your plants without using the synthetic spray on the plants themselves.

    Simply spray a ring on the ground about 6 feet away from the plant. Any bugs that come into contact with the permethrin will die or just evacuate the area.

    permethrin repellent to protect marijuana plants
    Permethrin-based repellent to protect your weed

    Sawyer: “For use on clothing, tents, and other gear, Sawyer Permethrin not only repels insects, they actually kill ticks, mosquitoes, chiggers, mites, and more than 55 other kinds of insects.”  

    Sounds great right? You can also spray it around your plants, available at

    There are also many organic repellants that you can create at home. Here’s one of my favorites:

    Oil Spray is a mixture of vegetable oil and soap, while soap spray is a soap and water solution.

    Both are basic insecticides, killing insects such as aphids, mites, beetles, and thrips.

    Other natural ingredients, such as neem oil, garlic, and chili powder can be added to the oil or soap sprays to increase effectiveness. For best results, spray plants at dusk or dawn.

    Other natural solutions include dusting the ground with diatomaceous earth, combining various insecticides into a single spray, and creating a spray out of tomato leaves. Here are some more recipes:

    Oil-Based Insecticide

    Oil spray insecticide can easily be made from mild soap (Castile works great) and vegetable oil.

    Oil based Insecticide for weed plants
    Oil-Based Insecticide

    This simple, yet effective spray will kill insects such as aphids, thrips, and mites by suffocation. The solution blocks their pores.

    To create your own solution, mix 1 cup of oil with 1 Tbl of soap. Mix it up well then dilute 2 teaspoons of it in 1 quart of water.

    Soap-Based Insecticide

    Soap spray insecticide is similar to oil spray, except it doesn’t have the vegetable oil.

    It also kills insects but is particularly useful for whiteflies, mites, and beetles.

    Soap based Insecticide for weed plants
    Soap-Based Insecticide

    Soap spray and oil spray can be used at any time, but are best applied near dawn or dusk.

    To make a soap-based insecticide mix 1 ½ tsp of mild soap with a quart of water. Spray it directly on our plants.

    Neem Oil Insecticide

    The Neem Tree has a natural defense system in the form of oil that makes it difficult for insects to survive.

    It is a hormone disrupter that keeps insect predators away. Neem Tree oil is safe for everything except insects and is also a power fungicide.

    Neem Oil Insecticide for weed plants
    Neem Oil Insecticide

    Use Neem oil insecticide to drive away and prevent insects, as well as fight powdery mildew and other fungal infections.

    Neem oil insecticide is available at most garden stores. You can also create your own mixture by combining 1 tsp of liquid soap with 2 tsp of neem oil in 1 quart of water.

    Garlic-Based Insecticide

    Although garlic may actually be an insect repellant rather than an insecticide, it is still quite effective.

    Garlic is ideal for at least slowing down an insect infestation. Spray as needed on infested plants.

    Use garlic based insecticide for weed plants
    Garlic can be used in a spray insecticide

    Ladybugs are good for your plants because they prey on larvae and other potential pests. 

    To make a garlic spray insecticide puree two bulbs (not cloves) of garlic in a blender with a little water.

    Leave it overnight, strain, and add ½ cup of vegetable oil, 1 tsp of mild soap and enough water to fill a quart. Mix 1 cup of this mixture with another quart of water. Spray as needed.

    Chili-based Insecticide

    Like garlic, chili pepper may be more insect repellent than anything else.

    Use it in your garden, but remember to wear gloves and protect your eyes, nose, and mouth. The spray won’t harm you, but it might hurt.

    Chili based Insecticide for weed plants
    Use chili as an insect repellent

    Create homemade chili spray out of fresh chili peppers, or use chili powder.

    If using powder, mix 1 Tbl of the powder with a few drops of liquid soap and 1 quart of water.

    From fresh peppers, puree ½ cup of peppers in a cup of water, add a quart of water and bring to a boil.

    Let the mixture cool, strain out the peppers and add a few drops of soap to the liquid.

    Your homemade spray is safe to spray directly on your plants.

    Diatomaceous Earth

    Fossilized algae buried deep in our earth is a natural resource that also makes a wonderful insecticide.

    Unlike other materials, diatomaceous earth does not poison or suffocate insects. It does something entirely different – it dehydrates them.

    Diatomaceous Earth for weed plants
    Diatomaceous Earth

    Diatomaceous earth is easy to find in most garden stores, but it’s generally sold in bulk.

    You won’t need much to get the job done. To use it, simply dust the area around your plants and on the plants as well. It will keep away insects, as well as snails and slugs.

    Don’t forget to reapply after it rains.

    All-in-one insecticide

    Sometimes, a mixture of a few natural remedies makes the best spray.

    To create an all-in-one insecticide, puree 1 garlic bulb, a small onion and a teaspoon of cayenne pepper powder.

    All-in-one insecticide - garlic, onion, and cayenne peppers for weed plants
    All-in-one insecticide

    Let the mixture sit – ideally for an hour. Strain the material and add 1 Tbl of liquid soap.

    Do not dilute. Spray on the upper- and undersides of leaves.  Store in the refrigerator for up to a week.

    Tomato Leaf Insecticide for weed plants
    Tomato leaf insecticide

    Tomato leaf insecticide

    Although hardly tried-and-true, tomato leaves may actually be a natural insecticide.

    As a member of the nightshade family, they contain alkaloids that keep aphids (and other insects) at bay.

    To make tomato leaf insecticide, steep 2 fresh tomato leaves in a quart of water overnight.

    Strain the material and spray the liquid directly on your plants’ leaves.

    Animal/pest control for marijuana plants

    Castor oil

    Castor oil is used to repel moles and gophers. Both are underground rodents clearing tunnels to their dens.

    Moles are bug eaters and will not harm your marijuana plants; they will divert the direction of their tunneling to circumvent the root systems.

    Gophers, on the other hand, will chew right through the roots, damaging the plants’ source of water and nutrient uptake.

    Castor oil for protecting cannabis plants
    Castor oil

    Gophers are repulsed by the taste and smell of castor oil.

    By soaking a piece of paper in castor oil and dropping it down the entrance to the burrow, these destructive critters will find a new location to build their ‘town’.

    Another option is a relatively new product in the form of granules. It consists of castor oil, soap and corn cob granules.

    Simply spread the granules, according to package directions, on the known areas and either water in or let Mother Nature do the work for you.

    The granules soak into the soil, releasing the repugnant smell both moles and gophers hate.

    This treatment is completely natural and actually benefits the soil or lawn. 

    Check your local garden center for granulated products. Castor oil in its raw form can be found at any drug store or supermarket.

    Cholecalciferol (vitamin D3)

    This is a rodent killer (rats and mice) that doesn’t kill them immediately, rather they die a slow death, taking three to four days for the poison to work its deed.

    Cholecalciferol Vitamin D3 for protecting cannabis plants

    Cholecalciferol introduces massive amounts of calcium into the rodents’ system, causing crystallization in their bloodstream, kidneys, stomach and lungs, eventually leading to heart failure.

    This treatment is toxic to household pets and humans, although the toxicity levels are lower than other available rat poisons.

    Quintox and Campaign are brand names under which the product is sold.


    Fumigants are a last resort in gopher and/or mole control. (Remember, moles pose no threat to your cannabis garden, as they eat bugs, not plants).

    Fumigants for protecting cannabis plants

    Fumigants come in the form of cartridges loaded with charcoal, sodium nitrate or sulfur and are placed in the burrow once the fuse is lit.

    This dispels toxic fumes into the tunnel.

    However, fumigants are the least reliable form of exterminating gophers due to the complexity and ever-winding path of the towns they build leading to their actual dens.

    Dens can be several feet below ground.

    Predator urine

    Predator urine is used to keep deer from trampling upon and eating your marijuana plants. 

    Deer chief predators are coyotes, mountain lions, wolves and wild dogs.

    Predator Urine for protecting cannabis plants
    Predator Urine

    The concept of predator urine as a deterrent follows the natural course of the food chain. Animals mark their territory with urine.

    When a deer smells the pee of a foe, it’ll stay away.

    Rather than apply the urine to Mary Jane, create a barrier by spreading it around perimeter plants or by applying it to strips of cloth attached to rope or cord around the garden.

    Place the treated strips about three feet apart along the entire length. Predator urine is available online.

    Putrescent eggs

    Rotten eggs are another effective deterrent for deer.

    Egg repellants are available commercially or you can make your own organic deer-be-gone at home.

    Rotten eggs for protecting cannabis plants
    Rotten eggs

    Blend together four to six eggs, four hot peppers, six cloves of garlic and five cups of water.

    Set the mixture in the sun for a couple of days to ferment and become rancid.

    Strain through cheesecloth and add to a spray bottle. This mixture can then be sprayed around the plant area. Repeat after rains.

    Zinc phosphide

    Zinc Phosphide is a fast acting rat poison. However, recent information released in April 2012 warns of the extreme toxic danger to humans and pets.

    Rat poison for protecting cannabis plants
    Rat poison

    It is not recommended to use this as rodent control for that reason. You certainly wouldn’t want this poison anywhere near Mary Jane!

    Use custom organic repellents

    Many growers have opted for pungent, organic repellents to keep pests away from both their indoor and outdoor plants.

    Concoctions like cinnamon oil, clove oil, and coriander oil have all had relative success without causing any damage to the plant.

    You can easily spray these repellents directly onto the cannabis leaves with no fear of any adverse reaction.

    Need seeds to grow healthy marijuana plants? Visit my online seed bank today!

    cannabis seeds

    Buy outdoor marijuana seeds

    • Most cost-effective way
    • No limitations on crop size
    • High-quality seeds
    • More space for higher yields
    • Feminized seeds for guaranteed bud

    Of course, different cannabis strains might have different reactions to any homemade organic repellents, and you should always test the repellents on an inconspicuous section of the plant to make sure no harm is done.

    We have actually developed a natural and organic product that protects your marijuana plants from all common pests and bugs.

    It is like a pesticide for marijuana plants, called the Marijuana Plant Protector System. Quickly have a look here: Bergman’s Plant Protector

    Marijuana Plant Protector Set

    Although it might not seem like it, it is actually more difficult to control pests indoors than it is outdoors.

    There’s really a small window of vulnerability between germination and seedling state when you have the plants outdoors.

    When they’re indoors, however, the pests can ravage your entire garden up until late in the vegetative state.

    Once you have bugs in the house, it’s hard to get them away from your marijuana plants.

    It’s always best to try using preventative measures so that bugs never become a problem in your indoor garden.

    Here’s a list with all pests on marijuana plants and how to treat them.

    Also read “Cannabis pests & bugs – Control and identification

    A solution like a Pot for Pot‘s windowsill grow keeps your grow nice and orderly as well. Be sure to check them out.

    We ship seeds only to the USA. For any growing-related questions please visit the marijuana support forum.

    Want to know when your plants are ready for harvest? Grab my free mini harvesting guide.

    Harvest Guide

    marijuana harvest guide
    • Time your harvest for Perfect Taste
    • Get THC levels for a Perfect High
    • Don’t waste any Precious Bud

      FAQ about How to keep bugs off weed plants

      What are some examples of homemade bug spray for weed plants?

      There are several types of homemade pesticides for weed plants. You can use neem oil insecticide, soap-based insecticide, garlic-based insecticide, vegetable-oil-based insecticide, and chili-based insecticide, to mention a few.

      How to keep bugs off plants without pesticides?

      Some pesticide-free methods include growing companion plants and using sterilized soil and fertilizer. You can also make use of natural predators, the urine of the pest’s enemies, or even build a fence.

      What bugs are good for weed plants?

      Ladybugs are good for your plants because they prey on larvae and other potential pests. 

      Happy growing!


      Avatar for Robert Bergman

      Robert Bergman

      Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations. His passion for growing led him to develop his own Gold Leaf strain. Now, Robert is dedicated to sharing his knowledge with the world.... [Read full bio]

      • Pinterest


      marijuana grow bible
      • Grow With My Quick Start Guide
      • Discover Secrets To Big Yields
      • Avoid Common Grow Mistakes

        34 comments on “How to keep bugs off weed plants: Marijuana pest control techniques”

        1. Hi Paul,

          Thanks for your question. Yes, it is. Cypress or Cedar mulch are commonly used to repel insects!
          We hope this helps!
          Happy growing,

        2. I am wondering if cedar mulch on top of the soil will Help keep insects off of my plants

        3. My question is concerning the tomato leaf spray. I’m in late flower, 6 weeks, and one of my Outdoor ladies is moderately infested with aphids. I am wondering if the spray can be used on the whole plant, buds and all or just the leaves? I am not finding anything about using it on the buds and I would like to know ASAP, thank you

        4. What do you recommend I do if my cannabis plant is already starting to Bud but it seems to have a problem with curled up dried leaves what do you recommend I do

        5. i would like to get the download again My hard drive went bad and i lost the
          grow bible can you please send me a copy
          thanks Ruben

        6. Can u use your urine and cbd oil in your water that u water ur marijuana plants. I USED STRAIGHT CBD OIL AND MY PLANTS WERE TOO RELAXED TO GROW

        7. Thank you for all you help over the years!!!!! This is the best guide out there. I 100% trust this book from experience!!!!

        8. James,

          I would never use Neem oil unless I absolutely had to. If you use Neem oil, then you would use it once you recognize and pest issue developing. Spray only the leaves in flower. Never spray on your buds.

        9. Can I use need oil as a prevention, if so when should I start, fighting off gnats at the moment seedlings are 12 days old

        10. Hi, how does this work please ? “The chili pepper plant also has a root system that gives off a chemical that protects your cannabis plants from rot. These plants are especially useful in areas with poor drainage or excess rainfall.”

        11. This is some really good information about keeping bugs away from these plants. It is cool that mint can keep bugs away. I wonder how they keep pest away from medical cannabis. It seems like those plants need special care and to be grown super carefully. I know that I wouldn’t want to take any drug that had really crazy chemicals on it when it was grown.

        12. I didn’t like that video that “”gives you clues to avoid mistakes”” when it really has the propose to sell you seeds lol

        13. Very interesting insight. I believe in professionals so this is a very useful article for everyone. Thank you very much for sharing..

        14. Can I get a list of pests and the homemade recipe for it please thank

        15. Using beneficial nematodes is also a natural and safe way to combat pests. Check out Steinernema feltiae.

        16. Hi Ann, what part of the world are you in? I have mine out in buckets but don’t no if helicopters fly about here? They are in da middle of furs surrounding them Hut open top for sun light. Any comments help wud b great

        17. Based on a Hyperspectral Sensor System, which ORINCON developed with Rancho Bernardo, Calif.-based Surface Optics Corporation, the new “pot-buster” camera can detect marijuana plants from an elevation of 5,000 feet, and from several hundred yards on the ground, against a backdrop of heavy vegetation. This sophisticated technology can even differentiate a marijuana plant from hemp, a similar, but legal plant used to make rope and clothing. This technology can also be used to detect environmental pollution.

        18. Ann,

          I really don’t know what to say. It is much harder to grow outside under those conditions. I must assume you are not a registered Med patient; Or, in a state allowing MJ to be grown.

          Corn is good as well. I have always chosen to grow indoors because, no one can serve a warrant on you unless you tell someone, or sell to someone, or show someone.

          Please join our support forum where we have several members that have these same issues, and you can open a discussion about your concerns.


        19. Jorge,

          If you are the guy; I have read your book. The Free Grow Bible is an ebook. Comes in pdf form. Thanks for your interest.

        20. Every year the helocopters fly over every August. They go ever different days. We had 3 last year and hid then in my flower bed. This year we planted 36. I bought sunflower seeds to put next to them in our woods. We 59 and afraid to put them OUT!!!!! Any one can help us?

        21. Im a outdoor grower and ive always found Neem oil in water with tiny drop of dish soap to be a winner for all. Neem works by addleing the bad bugs and keeping the good one’s Ie ladybirds.

        22. I usually grow indoors and dont have pest problems,…except for that one time. I decided to be cheap and instead of paying for soil (This was 20yrs ago) I dug up some from the back yard. It was terrible, huge pest problem, almost lost my crop.

        23. im a first time grower.and loving it.please send me the bible i tried dowloading it.oh and id also love to know if i can grow organicly without chemicals.or home made fertilisers.if so what can i use in since my plant is now two weeks after germinating.

        24. Hi,

          I grow marijuana indoors and i aways put a panty hose over my active air inlet so no bugs or insects can be sucked into the room. And if i still get thrips or aphids i spray them with neem oil, which always works for me.