Thrips on marijuana plants

Thrips are small (smaller than 0.06” in length), insects with wings that feed off of the liquids of the marijuana plant through poking a hole in the plant and sucking up everything inside.

Their wings aren’t much help for flying as they rely on the wind to carry them from one place to another. They have six legs, are shaped like a cigar and their butts are pointy.

Thrips can do some serious damage to your marijuana plants so make sure you know how to identify them and how to get rid of them.

Signs of thrips

At the point where the insect attacked, the harm they caused will show up as bronze or silver-colored defects on the leaves and/or stems. Your plants leaves will lack chlorophyll, become dry, brown and brittle.

Thrips on marijuana plants
Thrips on marijuana plants

Thrips usually feed off of buds and new leaves so, this is where the problem happens most of the time. Thrips are something to be worried about since they are common causes for plant viruses.

Plants with strong genetics have less chances of getting sick and are less vulnerable to pests and diseases. I have created multiple grow sets which features all you need in order to grow healthy plants from seed to harvest!

buy all-in-one marijuana grow set

Get your grow set

Outdoor marijuana plants generally have less of an issue with this unlike greenhouse gardens or indoor grow rooms where this is more common. Thrips take a liking to the buds for doing their dirty work. If you ever notice edges that appear burned, then you have a host of thrips there. All you have to do is shake the plants to get them off and away from your plants.

Not sure if thrips are causing the damage to your marijuana plants? Check the article Marijuana pest and bug control for a list with pictures of all pests and bugs

Also read Cannabis Pests & Bugs – Control And Identification

How to get rid of thrips

A great way you can resolve the problem is by misting your plants with a solution. Do this right before the light are going off, because if you don’t the leaves will burn. You can also use your preferred insecticide to get rid of thrips. Their enemies are the Amblyseius Cucumeris, which can ward them off.

Get rid of thrips on weed plants
Get rid of thrips on weed plants

Thrips are easily run off by wasps, predatory mites and neem oil. Using the right compost combination on the soil prior to planting helps keep healthy nematodes that will attack the pupae that fall to the ground.

A commercial product like Bug Blaster will always to the job. If you want to make sure to get rid of all of them, take a look at my Plant Protector set, which features Bug Blaster. You can use that to specifically target (and defeat) thrips.

Marijuana plant protector

Bergman’s Plant Protector

  • Protect your plants from diseases and harmful pests.
  • Consists of three 20 ml bottles
  • Enough plant protection system supplies for up to 20 plants
  • Suitable for soil, hydroponic and all other grow mediums

Marijuana plant symptoms

Even though thrips are tiny, you can still see them moving on the leaves. You definitely want to be on the lookout for these, especially when growing in a greenhouse. You don’t want these bad boys eating away at the juices in your leaves. Protect your plants by taking the necessary precautions. Observe your plants for any possible signs of thrips and follow the steps above to keep your plant flourishing.

Recognize the marijuana plant symptoms caused by thrips:

  • Damage to buds and younger leaves
  • Shiny, silvery spots on leaves and/or stems
  • Bronze spots on leaves and/or stems
  • Leaves are dry, brittle and a brown color

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible

Happy growing!


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Mr Robert Bergman PhD


Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile

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19 comments on “Thrips on marijuana plants”

  1. Tracey,

    You can try insecticidal soap but, only once and once again 2 weeks later. IN flower we cannot be spraying.

    Also; I suggest you join our support forum and show us a picture or 2 for a more informed answer.

  2. Tracey,

    You can try insecticidal soap buy, only once and once again 2 weeks later. IN flower we cannot be spraying.

  3. Tracey,

    You can try insecticidal soap buy, only once and once again 2 weeks later. IN flower we cannot be spraying.

  4. I have thrips on my flowering plants, maybe 3 weeks from harvest. Can I use anything on them at this point? I don’t want to ruin the buds if I can help it. And how do I sterilize the grow tent once they’re harvested? Thank you!

  5. mj,

    Gently wash all the leaves, and monitor for further activity. Look closely for eggs or anything foreign on the leaves. All you can do after harvest is use a microscope of some kind to make sure you will not be ingesting any remnants of the Thrips.

  6. How about if you find nymphs just days before harvest? I am about a week away from harvest, and just found the little white bugs.

  7. Frank,

    You have to be proactive, You always have to continue treatment for 2-4 weeks to kill all the hatchlings (larvae).

  8. I am a seasonal smoker and have smoked the best and worst , I’m looking for a kick arse strain that has a high THC resulting in a chunky bud

  9. […] oil is an effective defense against ants, aphids, fungus gnats, leaf miners, mealy bugs, scale, thrips, white flies and root weevils. Other components in neem oil have fungicidal properties combating […]

  10. Hard to say without a picture. Please join our support forum and start a topic for a better chance to figure this out.

  11. got a green bug that sidles under the leaf when approached. They fly. They’re about 3/8″ long. Was suggested they were of the grasshopper family. No plant damage. These are out door plants.

  12. […] As with most pests, the best way to deal with thrips is preventative action. Stop them before they even get into your garden. Using the highest quality compost and maintaining a clean environment for your plants is a good way to help you in this regard. If you already have thrips infesting your plants, however,  you’ll need to get rid of them. There are a number of predatory mites which you can introduce to the area. This will help curb their population. Alternatively, you can spray them with a mix of neem oil and water. This will knock them off the plant and help protect your flowers. Read more about Thrips on marijuana plants […]