When Things Go Wrong


Cannabis plants are susceptible to a wide variety of pests and pathogens that can devastate your grow, and vector diseases such as pathogenic fungus, bacteria, and viroids. This class offers an understanding of threats as well as ways to prevent and treat them with Integrated Pest Management and nutrient balancing.

Course Overview

First, we start with a discussion of pests. More than 300 pest species have been identified on cannabis plants; even those typically not considered “devastating” to a cannabis grow can still vector diseases such as pathogenic fungus, bacteria, and viruses. To prevent and treat pest problems, cannabis growers need to understand the life cycle of common pests and the environments in which they thrive. In this course, we review the most common known pests that affect cannabis and discuss some general treatment options.

Then, we move on to pathogens that lead to disease in cannabis plants. We identify some common pathogens found in cannabis, along with the diseases they can cause and the symptoms of those diseases. Then, we explore the conditions which must be present for a disease to emerge and offer strategies for controlling pathogens and disease in a cannabis cultivation operation.

From there, we move on to prevention, treatment, and IPM. We present strategies for preventing pest and pathogen infestation, such as sanitation, environmental controls, cultivating beneficial microorganisms, companion planting, and the introduction of beneficial predators. We then review some of the treatments available to control a pest or pathogen infestation and discuss how to do so safely and efficiently. We then introduce the concept of integrated pest management and provide resources for learning more about the practice.

Finally, we discuss nutrient disorders. The delivery of essential nutrients through fertilization is an essential factor in successful cannabis production. Under-fertilization can cause nutrient deficiency, whereas over-fertilization can lead to salt accumulation in the root zone and cause “nutrient lockout.” Both can have a negative impact on yield. In this class, we learn more about how nutrients travel through the plant, which will help us better understand how nutrient disorders occur and how to identify them. We then introduce some of the most common cannabis nutrient disorders and all the complexities that go along with diagnosing, preventing, and responding to nutrient issues in your cannabis plants.


  • Pests
  • Pathogens
  • Prevention, Treatment, and IPM
  • Nutrient Disorders