The 3 Most Common Cannabis Pests

The 3 Most Common Cannabis Pests & How to Get Rid of Them

By Abby Hutmacher

The 3 Most Common Cannabis Pests & How to Get Rid of Them

Bugs and pests love to set up shop on pot plants. Though companion planting can help reduce the number of pests your outdoor marijuana grow will encounter, successful cannabis cultivation requires more diligent attention. To protect your pot plants from pest damage, keep your eyes peeled for these common pests in marijuana grows.

Spider Mites

Spider Mite

Spider Mite

  • Identifying Spider Mites:

Spider mites can be identified by their characteristic appearance (small, oval bugs with six to eight legs) or the damage they cause by nibbling away at the chlorophyll leaving little white or yellow spots in their wake. They also spin webs to protect their offspring so be on the look-out for the silky string on leaves and buds.

  • Problems Caused by Spider Mites:

Plants need chlorophyll to grow, so an excessive amount of spider mites munching on chlorophyll can cause significant damage or even death to a cannabis plant. Not only that, but their webs are very sticky and difficult to remove which could result in an impure harvest and a non-usable product.

  • How to Get Rid of/Prevent Spider Mites:

When growing indoors, it’s best to avoid the whole spider mite fiasco to begin with. This can be done by ensuring completely sanitary conditions in your grow room including sanitary soil and supplies, air supply and yourself. Always wash hands and clothing before entering an indoor grow area and never allow pets access to the room.

If spider mites are already an issue, you can try to clean them off with a high-powered hose (though it’s best not to do this while flowering) or neem oil, an organic bio-pesticide that has been deemed safe for use on vegetables and other flowering plants. Remember to repeat the cleaning process over the next few days to kill off both mites and eggs.




  • Identifying Aphids:

Aphids are tiny, yellow winged bugs that commonly set up shop under cannabis leaves. They reproduce quickly (females may give live birth as often as 12 times per day) so infestations can happen quickly and should be remedied immediately. Because they consume nutrients within cannabis, the resulting leaves will appear yellow and wilted.

  • Problems Caused by Aphids:

Aphids not only eat cannabis plants, but their feces attract ants thus creating an even larger infestation problem. They have also been known to introduce viruses from near-by plants which may stunt growth or slow the production of flowers.

  • How to Get Rid of/Prevent Aphids:

Though Mother Nature can help keep an aphid infestation in check with beneficial pests like ladybugs or parasitic wasps, you can help speed the process with the use of garlic or tomato leaf water. To make the solution, simply soak tomato leaves or garlic and mineral oil in water for 12 – 24 hours, strain the mixture then apply to one small area of the plant. If the leaves yellow after application, dilute the solution and try again.

Fungus Gnats

Fungus Gnats

Fungus Gnats

  • Identifying Fungus Gnats:

Little black bugs swarming around the soil and lower portion of your marijuana plant are called fungus gnats. They are only three to five millimeters in size and produce larva with a dark head and transparent body. Females lay eggs within the first few inches of moist soil and larva can commonly be found in water run-off.

  • Problems Caused by Fungus Gnats:

Though fungus gnats will not eat leaves or flowers (in fact, adult gnats don’t eat anything), they can damage roots and reduce soil drainage weakening the plant and making it more susceptible to damage and infestation.

  • How to Get Rid of/Prevent Fungus Gnats:

Fungus gnats need moist soil to reproduce so the best way to prevent fungus gnat infestation is to keep the top layer of soil as dry as possible. You can also place a cloth over the soil to prevent females from laying eggs. Also remember to keep screens on windows and doors closed at all times to keep them from getting to your indoor grow in the first place.

After all of the time, money and effort that goes into a cannabis grow, it would be a shame to watch the harvest wither and die at the hands of pesky garden pests. Stop critters from overtaking your pot plants with these simple tips for cannabis pest prevention.


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