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Cannabis Pests and Diseases That May Affect Your Yield

Cannabis Pests and Diseases That May Affect Your Yield

The growing popularity of cannabis cultivation worldwide has brought increased focus to improving yields and avoiding cannabis pests and diseases.

Cannabis growers seek solutions to achieve the maximum results from their plants by adopting various modern tools and techniques.

Among the various threats to cannabis yields, bug infestations and infections remain challenging even for experienced cultivators. 


Cannabis Pests and Diseases That May Affect Your Yield

Even though cannabis is a super herb with powerful healing properties, it is still prone to pathogen attacks that can severely affect yield quality.

Whether you are working with an indoor or outdoor cannabis garden, taking the necessary precautions and preventive measures to avoid cannabis leaf problems is crucial to achieving a healthy bounty post-harvest.

Here we will explore the effects of bugs and infections on cannabis yield and some practical ways of curbing the losses.  

The Effects Of Marijuana Plant Diseases Your On Yield 

Cannabis diseases induced by soil-borne or above the ground pests and insects can affect crop production in several ways. They reduce available resources such as nutrients and water to the plant that can influence yield quality and quantity. 

In the case of cannabis, the infections can also affect the potency of the buds. Cannabinoid levels are crucial to induce therapeutic benefits through infused products such as CBD oil or THC weed gummies.

Therefore, using buds with high potency and quality is necessary to achieve the best benefits from these natural compounds. 

Climate variations are sometimes a favoring factor for the multiplication of these pathogens that can impact soil fertility.  They also encourage developing new diseases and pests that might be resilient to existing control methods. 

In most crops, cannabis pest infestation and infections show immediate visual symptoms that enable rapid diagnosis. 
cannabis leaf problems

Common symptoms include wilting, stunted growth, yellowish markings on the leaves, failure to flower, necrosis, rolled leaves.

In discovering these symptoms, immediate steps to eliminate the infestation through insecticides and pesticides are crucial. This way, you can reduce the threat against the yield. 

Common Marijuana Plant Diseases To Watch Out For 

Fungal Infections  

Gray mold is one of the most common infections that leads to a strange coloration on the buds, and bud leaves turning yellow.

Pythium is another fungal infection that leads to rotting the root system or lower sections of the stem, especially in young plants.  

Mildew, leaf molds, and filamentous fungi are other conditions that could reduce the quality of yield. Maintaining a clean and dry environment is crucial to reduce the appearance and spread of fungal infections. 

Ensure the grow area is sufficiently ventilated and remove fallen leaves from around the plant to eliminate bug infestations. In case of a fungi problem during early flowering, remove the infected branches immediately. 

marijuana plant diseases

Be careful while doing so as fungi release spores that could lead to further spread of the infection. Cover the area with a plastic bag before trimming for best results.

Fusarium is the deadliest fungi that also lead to root rot. The pathogen can turn stem red from inside and burst in certain areas that expose the plant to other pests and insects. 

Unlike other fungi on the list, Fusarium does not have any effective treatment, and therefore taking necessary preventive measures to avoid it would be the best choice.

Spider Mites

Spider mites are also a common infection in cannabis plants that are extremely hard to eliminate. The sign of infestation includes speckles on the leaves and tiny mites on the underside of the leaf.

Leaves typically turn yellow shortly after the infestations, and the webs start to appear over the leaves and the buds that can affect the yield. Unlike fungal infections, spider mites thrive in dry conditions and hot weather. 

Therefore maintaining the optimum humidity and temperature levels is crucial to reduce the possibility of infection. Also, using organic pesticides and insecticides during the early stages of the infestations can cut down losses. 


Aphids are among the most common cannabis pests. Several different species of the insect can affect the yield. Most aphids live on the foliage, whereas some reside in the root system. 

They are quite challenging to identify on the plant and typically thrive in moist environments. Microbial insecticide application in the early stages of detection can be useful to reduce damage.

Running the dehumidifier for a day or two can help to reduce moisture that could be helpful in detecting these kind of pests.

cannabis pests and diseases


Thrips have increasingly become a threat to cannabis yield in several parts of the globe. Although they do not affect the yield severely, early detection can help curb the damage significantly. 

If you spot thrips during regular scouting, send them to a lab for identification. You can include BCA’s (Biocontrol Agents) in combination with spray products to rid them immediately. 

Tips To Reduce Cannabis Pests Infections and Damage 

  1. Keep the growing area clean. Use sterilized tools, containers while establishing new mother plants as fungal infections easily transmit through these mediums. Use a diluted household bleach solution to clean the tools used on the plants. 
  2. Quarantine new arrivals before adding them to the growing area. Assess the plants for diseases to avoid infecting the entire lot. 
  3. The cheapest way to reduce the risk of spread is to eliminate the infected plant from the growing area and destroy them immediately.  

Related articles on growing cannabis: 

Wrapping Up Our Cannabis Pests and Diseases Guide

Cannabis pests and insects infestation can be a challenging problem, especially in organic farming practices. Diseases caused by pest infestations can threaten the overall health of the crop and severely degrade the quality of yield.

It can rupture the nutrient pathways that influence the potency of the plant. Early detection and countermeasures to cope with cannabis pests and diseases can help reduce the intensity of the damage.

About the Author Ann Katelyn

I'm Ann Katelyn, Creator and Chief Author of Sumo Gardener. Since I was a child I've always been fascinated with plants and gardens, and as an adult this has developed into my most loved hobby. I have dedicated most of my life to gardening and started Sumo Gardener as a way to express my knowledge about gardening with the hope of helping other people's gardens thrive.

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