Pest Management

Thwarting Thrips: Protecting Cannabis Crops and Boosting Growth

A grower inspecting a cannabis leaf with a magnifying glass for thrips.

How do you get rid of thrips on cannabis leaves?

Thrips, being the tiny tissue-piercing critters they are, can be quite the nuisance for your cannabis plants. However, a well-thought-out strategy can keep them at bay. Organic methods such as applying neem oil or insecticidal soap are common and effective measures. A thorough cleanse with these substances can be quite the eviction notice for thrips. Additionally, the practice of changing the substrate between crops, and introducing beneficial insects like Amblyseius swirskii and ladybugs are also preventive measures against thrip infestations​.

A close-up view of thrips on a cannabis leaf.

Do thrips affect cannabis yield?

Close up of a living thrip on a live cannabis leaf

Yes, thrips do affect the yield of cannabis plants adversely. They feed on the sap of the plants, causing stress and hampering their growth. The feeding activity of thrips can lead to visible damage, including discolored patches and silvery streaks on leaves, which in turn, affects the plant’s ability to photosynthesize efficiently. This reduction in photosynthesis can lead to a decrease in the energy the plant has available for growth and bud development, ultimately impacting the overall yield negatively. The damage inflicted by thrips can also make the plants more susceptible to other pests and diseases, which can further degrade the quality and quantity of the yield. Hence, controlling thrips infestation is essential to ensure a healthy growth cycle and a good yield for cannabis cultivators.

A side-by-side comparison of a thriving cannabis plant and one affected by thrips.

What is the best thrip control for cannabis?

An illustration showing a cannabis plant with a protective barrier against thrips.

The best control measures for thrips on cannabis entail a combination of preventive and treatment actions. Here’s a summary:

A cannabis leaf with a protective shield emblem, symbolizing defense against thrips.
  1. Prevention:
    • Sanitation: Keep your growing area clean and free of plant debris.
    • Monitoring: Regularly inspect your plants for signs of thrips or damage, especially on new growth and flower buds.
    • Physical Barriers: Employ physical barriers like row covers or screen ventilations to keep thrips away.
    • Companion Planting: Planting thrip-repellent plants or those that attract natural predators can be helpful.
    • Biological Control: Introduce beneficial insects like ladybugs and lacewings, which are natural predators of thrips​​.
  2. Treatment:
    • Neem Oil: Neem oil is a natural insecticide that can be very effective against thrips without harming the cannabis plant​​.
    • Insecticidal Soap: Soap sprays can suffocate thrips on contact.
    • Beneficial Insects: As mentioned, beneficial insects can help control thrip populations.
    • Diatomaceous Earth: Sprinkle diatomaceous earth around your growing area to deter thrips.
    • Organic Insecticides: Utilize organic insecticides like potassium soap and pyrethrins​​.
    • Sticky Traps: Place yellow sticky traps around the plants to catch thrips.
    • Chemical Control: If the infestation is severe, chemical insecticides may be used as a last resort, keeping in mind they can be harmful.
  3. Cultural Control:
    • Resistant Varieties: Choose cannabis varieties that are resistant to thrips.
    • Proper Watering and Fertilization: Maintaining good plant health can help deter pests.
A cannabis grower applying an organic spray to protect plants against thrips.

These measures, used in conjunction or as needed, can provide effective control of thrips, ensuring the health and productivity of your cannabis plants. Each grower might find that a combination of these methods works best in their particular situation and environment.

Keeping your grow area clean and well-ventilated is crucial. However, when thrips find their way in, beneficial insects like ladybugs and Amblyseius Cucumeris can help control thrip populations. Moreover, spraying natural insecticides such as neem oil or potassium soap can deter these pests. Introducing predatory species that protect your plants rather than harm them is also a viable option​.

Beneficial natural predators such as ladybugs and lacewings near a cannabis plant, showcasing their role in thrip control.

What are some thrip-repellent plants?

Several plants are believed to have thrip-repelling properties, and incorporating them in or around your cannabis garden may aid in deterring thrips. Here are some plants that are mentioned across various sources to have thrip-repellent characteristics:

A side-by-side comparison of a damaged cannabis plant and a healthy one, underscoring the adverse effects of thrips.
  1. Garlic: Planting garlic, especially around tomato plants, can help repel thrips. The suggested planting rate is 1 garlic plant for every 270 square feet​1​.
  2. Basil: Besides being a culinary herb, basil is also known for its insect-repelling properties. It can help keep flies and mosquitoes at bay, and some sources suggest it may repel thrips as well​2​.
  3. Oregano: While oregano is primarily mentioned for repelling other insects like mosquitoes, cabbage butterflies, and cucumber beetles, it’s part of a family of aromatic herbs that might have some effect against thrips​1​.
  4. Chives and Catnip: These are other herbs that are often mentioned alongside basil as having insect-repelling properties​2​.
  5. Various Flowers: Planting certain flowers can attract beneficial insects like pirate bugs, lacewings, and ladybugs, which are natural predators of thrips, thus helping in controlling thrip populations indirectly​.

It’s crucial to note that while these plants are believed to repel thrips, there’s no conclusive evidence supporting their effectiveness, and some of the plants believed to be thrip-repellent can still suffer from thrip attacks​​. Hence, it might be beneficial to employ a combination of methods for controlling thrips in your cannabis garden, such as maintaining good sanitation, introducing predatory insects, and applying organic insecticides alongside planting these potentially repellent plants.

How do you treat thrips in Canada?

A flowchart illustrating steps for effective thrip control in cannabis cultivation.

The cool climate in Canada necessitates keeping indoor growing areas clean. Employing diatomaceous earth around your grow area can deter thrips. Spraying insecticidal soap or neem oil, coupled with the introduction of beneficial insects, can keep thrips under control. Also, using organic insecticides like potassium soap and pyrethrins, and placing yellow sticky traps in the grow room are recommended measures​​.

What does thrip damage look like on Cannabis?

Thrip Damage on a cannabis leaf

The damage caused by thrips is distinctive. They leave behind silvery-white streaks and spots, black droppings, curling or distortion of young leaves and fruits, spotted patterns on flowers, and other visible signs on the leaves and buds. This damage can be glaring in a cannabis garden, transforming vibrant plant colors to a pale, speckled yellow hue​​.

What attracts thrips?

Thrip Damage on Alien genetics cannabis leaf

The lush greenery and fragrant aroma of cannabis plants are quite the invitation for thrips. They are also attracted to the colors and scents of certain other plants, so keeping such plants away from your cannabis could act as a preventive measure.

What is the damaging stage of thrips?

Picture of underside of a cannabis leaf that has thrip damage on it

The larvae and adult stages are where thrips cause the most havoc. They feed voraciously on your plants, leaving a trail of destruction.

Thrip damage on cannabis plants can manifest in several ways, making them look unhealthy and stressed. Here’s what to look out for when inspecting your plants for thrip damage:

A Cannabis Plant that has been Damaged by Thrips
  1. Silvery Streaks and Spots: One of the hallmark signs of thrip infestation is the appearance of silvery-white streaks and spots on the leaves, a result of thrips feeding on the plant tissue.
  2. Black Fecal Spots: Thrips leave behind tiny black fecal spots on the leaves, which are another indicator of their presence.
  3. Curling or Distortion of Leaves and Fruits: Young leaves and budding fruits may show signs of curling or distortion as a result of thrip feeding.
  4. Spotted Patterns on Flowers: The flowers may exhibit spotted patterns, another sign of thrip activity.
  5. Yellow Speckles on Leaves: The presence of yellow speckles on the leaves is a sign of damage.
  6. Silvery Sheen on Mature Leaves: Older leaves might display a silvery sheen as a result of the feeding activity of thrips.
  7. White Discolored Patches on Leaves: Discoloration in the form of white patches can appear on leaves.
  8. Pale or Mottled Appearance on Leaves: The leaves may lose their vibrant green color and appear pale or mottled.
  9. Visible Damage on Fruits and Shoots: You might notice visible damage on fruits and shoots.
  10. Hindered Growth Progression: Thrip damage can hinder the growth progression of the cannabis plant, making it look stunted.
  11. Discoloration and Blemishes on Flower Petals: The flower petals might show discoloration and blemishes.
  12. Signs of Wilting and Evident Scarring on Plant Parts: Parts of the plant may wilt, and there may be evident scarring on plant parts.
  13. Increased Incidence of Plant Viral Diseases: Thrip damage can also make plants more susceptible to viral diseases​​.
Beneficial natural predators such as ladybugs and lacewings near a cannabis plant, showcasing their role in thrip control.

Thrip damage can significantly affect the aesthetics, health, and yield of your cannabis plants, making it essential to identify and address thrip infestations promptly.

Do thrips transmit plant viruses?

Yes, thrips can act as vectors for plant viruses, like the Tomato Spotted Wilt Virus, which is detrimental to cannabis plants.

What kills thrips the best?

A cannabis grower applying a natural thrip repellent spray to a cannabis plant.

A blend of good hygiene, deploying natural predators like ladybugs, and using organic insecticidal solutions is your best defense against thrips. Regular checks and early intervention are also key to managing thrip populations.

The most effective control against thrips often involves a multi-faceted approach. Here are several methods known to be effective in managing or eradicating thrips:

A magnified view of thrips actively feeding on plant tissue, illustrating the destruction they inflict during their damaging phase.
  1. Neem Oil: Neem oil is a natural insecticide that can be effective against thrips without harming your cannabis plants​.
  2. Insecticidal Soap: Insecticidal soap sprays can suffocate thrips on contact, making them a safe and effective option.
  3. Beneficial Insects: Introducing natural predators of thrips such as ladybugs, lacewings, and predatory mites can help control thrip populations​​.
  4. Diatomaceous Earth: Sprinkling diatomaceous earth around your growing area can deter thrips by dehydrating them upon contact.
  5. Organic Insecticides: Organic insecticides like potassium soap and pyrethrins can be effective against thrips without the harsh effects of chemicals​.
  6. Sticky Traps: Placing yellow sticky traps around the plants can help catch thrips, providing both a measure of control and a means of monitoring thrip populations.
  7. Chemical Control: In severe infestations, chemical insecticides might be considered. However, they should be used as a last resort due to their potential to harm both the plants and beneficial insects.
  8. Biological Control Agents: Utilizing microbial control agents like Beauveria bassiana, a fungus that infects and kills thrips, can also be an effective strategy.
  9. Physical Removal: In minor infestations, physically removing thrips by hand or by pruning infested plant parts can be effective.
  10. Cultural Controls: Maintaining a clean, well-ventilated growing environment and practicing crop rotation can help prevent and manage thrip infestations.
  11. Row Covers or Screened Ventilations: Employing physical barriers can prevent thrips from accessing your plants.
A representation of preventive measures against thrips, visualized as a protective shield around a cannabis plant.

Each grower might find that a combination of these methods works best in their particular situation and environment. It’s essential to consider the level of infestation, the specific needs and conditions of your growing area, and the potential impact on your plants and beneficial insects when choosing the methods to employ against thrips.

What is the best organic thrip killer?

A representation of various organic and chemical thrip control methods surrounding a cannabis plant.
Neem OilNatural, safe for plants, effective against various pests,May require multiple applications, strong smell,
also has fungicidal properties.can be expensive.
Insecticidal SoapSafe, effective on contact, easy to make at home or purchase.Must directly contact pests, can require repeated
applications, may dry out plant foliage.
Beneficial InsectsNatural predators, provide ongoing control, safe for plants.May take time to establish populations, may not fully
eradicate thrips, effectiveness can be influenced by
environmental factors.
Diatomaceous EarthNatural, effective desiccant, easy to apply.Must be reapplied after rain or watering, may not be
effective in high humidity.
Organic InsecticidesSafer than chemical insecticides, effective against variousMay require multiple applications, cost.
(e.g., potassium soap,pests.
Sticky TrapsNon-toxic, also serve as monitoring tools.Not a solution for eradication, can become messy.
Biological Control AgentsTargeted, effective, natural.May require careful application, cost, may take time to
(e.g., Beauveria bassiana)see results.
Organic Thrip Killers in Table Format

What eats adult thrips?

Beneficial natural predators such as ladybugs and lacewings near a cannabis plant, showcasing their role in thrip control.

Ladybugs and lacewings are the knights in shining armor here. They swoop in to feast on the villainous thrips, helping to control their population.

Summary Symptoms, Diagnosis, Solutions

A close-up view of thrips larvae causing visible damage on a cannabis leaf
  • Symptoms: Look out for silvery streaks, black dots, and discolored patches on leaves.
  • Diagnosis: Inspecting under leaves and around buds will usually reveal these tiny trespassers.
  • Solutions: Employ neem oil, beneficial bugs, and maintain a clean, well-ventilated growing environment to bid farewell to thrips.
Live thrip on top of a growing cannabis leaf


  • Q: Can thrips become resistant to chemical pesticides?
    • A: Yes, hence organic solutions and natural predators are often better choices.
  • Q: How often should I check my plants for thrips?
    • A: Regular checks, at least once a week, can help catch an infestation early on.

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