When it comes to cannabis pests, the old saying, “An ounce of prevention is worth a pound of cure,” not only applies, but is key to growing healthy plants. Pest prevention is foremost in the overall growth process. Outsmarting the enemy can prevent time wasted over dealing with this most irritating and concerning factor for many cannabis growers.

Enough time should be allowed during the setup stage of growing cannabis to make sure your plants have effective lighting, maximum air quality, sufficient water cleanliness and proper room conditions because all of these contribute to overall pest prevention, Hand washing upon entering the area where the plants are grown also prevents the spread of any diseases that might prove harmful to your plants. And, your plants should also be inspected every time they are attended to, so that changes can be identified immediately.

Below 13E has provided a list of the most common cannabis pests, along with some natural ways to prevent them from damaging your plant:  

  • Spider Mites—spider mites love heat and hate wind, so adequate air circulation is a must. Spider mites do not survive in cold, humid temperatures. Keeping plants hydrated, moist and in a humid environment helps prevent this type of infestation.
  • White Flies—growing marigolds, Chinese carnations and/or basil has been proven to help prevent these pests. Also helpful is to make sure to examine the underside of the cannabis leaf, where white flies tend to reside.  
  • Fungus Nats—keeping the soil as dry as can be tolerated discourages fungus gnats from taking over your plants. Placing a cloth on top of the soil also discourages eggs from being laid. Plus, planting a potato in the soil, then checking it for larvae, is also effective.
  • Gray Mold—another nightmare pest for cannabis growers is gray mold. This pest can destroy cannabis buds in just a few days. Because gray mold has a hard time surviving in too low or too high humidity, the desirable range to grow cannabis is in the 46% to 53% humidity range.
  • Root Rot—one of the biggest factors for root rot is overwatering, so make sure to study and only provide the appropriate amount of water for your plants. Keeping your root zone and water temperature between 67 – 71 degrees Fahrenheit also discourages root rot.


Other pests to watch out for are: powdery mildew, damping off, green algae and downy mildew. And remember, a plant without the proper nutrients has no chance to survive. Weak plants attract pests, so make sure to grow your plants in the best environment possible with the best nutrients available. Read more about micronutrient care here!