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How To Kill Spider Mites On Your Marijuana Plants


Spider mites are perhaps the most damaging invaders to hit your marijuana plants, and so its extremely important you know how to kill spider mites on your marijuana plants. Considered arachnids rather than insects, spider mites have eight legs and no antennae. They are minutely and extremely hard to see with the naked eye. Spider mites typically make their homes on the underside of leaves and will spin a silky web as a means of protecting their colony and eggs from predators.

If you see fine white connections between leaves, chances are you have spider mites.

Close up of Spider Mites

Spider mites have little ‘teeth’ with which they can puncture a single plant cell and extract chlorophyll, which is necessary for photosynthesis in all plant life. Eggs hatch within three days with the spider mite becoming sexually mature in a mere five days. This means they can reproduce at a rapid rate, thus causing major damage to your crop.

Because they reproduce rapidly, spider mites have the potential of causing major damage to your marijuana plants. A mature female can produce literally millions of offspring within a month’s time. Astonishing that something so small can be so detrimental and in such massive numbers!

Uncontrolled spider mite infestation can cause major crop damage and/or failure. By following the planting practices mentioned below, you can deter the infestation of spider mites.

How To Kill Spider Mites On Your Marijuana Plants

Preventative Measures

Organic compost and mulch added to the planting site deters these microscopic warriors from invading your marijuana plants by encouraging the presence of predatory mites which feed on the destructive spider mites.

Ladybugs also feed on spider mites. They can be purchased online, but will more than likely fly away once they no longer have a food source available to them. You may see the sudden appearance of ladybugs if spider mites are present and can save yourself the trouble of purchasing them. Mother Nature works that way!

Already have Spider Mites on your marijuana plants?

If, in spite of taking preventative measures, you still see evidence of spider mites, hit your cannabis with a hard water spray three mornings in a row. The water pressure will remove the bugs and their protective webs from the leaves, causing them to fall to the ground and debilitating their movement. They will no longer be able to reach the leaves and will die from starvation. If you want to try an organic spray, you can find a great one at this link here.

Another organic solution to spider mites feasting on your marijuana plants is to take a hand held vacuum and suck them off the leaves. This will take some time, but will remove the damaging pests. When finished, empty the contents of the vacuum into a plastic bag and freeze. Spider mites thrive in high temperatures, thus will die from the cold. Discard the bag on garbage day.

Want to know more about growing marijuana? Get a free guide about growing marijuana at this link here. Order some high quality marijuana seeds at this link here.



About Author

Robert Bergman is a master marijuana grower. Robert Bergman is the author of 'Marijuana Plant Care' and 'The Marijuana Grow Bible'.


  1. sorry have to comment, I was taking you seriously until the part where you say to suck the spider mites off the leaves with a hand held vacuum . Now I will not be taking this info seriously at all.

  2. My question is this…since these mite have a particular environment in which they thrive, why not change the environment so they CAN’T thrive?? So on an inside grow, where you can control temp and humidity, why not lower the room temp and introduce a higher humidity? I have heard people say that a higher humidity will introduce a possibility for mold growth, but if the water you humidify with is a mixture of 50% clean/filtered/distilled water with 50% propolyne glycol it will act as an antifungal AND maintain an nice 70% humidity…what are your thoughts on this?

  3. David Kellerlllllll on

    I have an issue with different kinds of insects and at night I spray heavy water mixed with hobenerjo chillies lemon juice and vinigar. Do you think that will hurt my plants?

  4. Hot pepper spray also works well, since it is absorbed through the skin. It will kill them almost instantly without harming the plant (It may even force the plant to make more resin, which means higher potency).

  5. I found that Dr. Bronner’s peppermint soap, about a tablespoon or so to a quart of H2O, works well. Mix small batches up fresh for best results. This kills/repels all sorts of bad bugs.

  6. Whoever wrote this is a complete moron. Ladybugs are not effective. They are a complete waste of money. If you want to use a predatory insect Green Landings or Predator Mites are the way to go. DO NOT EVER spray your plants with anything at the beginning of the light cycle as that will cause the liquid droplets on the leaves to act as a magnifying glass and your leaves will either burn, wrinkle or both. If you want to use an organic spray you can use Spinosad which is a bacteria that covers the plants and causes death to all bugs who consume the plant. Once ingested the bacteria eats its host from the inside out. And it should be sprayed right before lights out, coat everything. If you’re in flower I would recommend alternate spraying with Spinosad one day and Power Wash by “That Stuff” the next. If you don’t do that your flowers will taste like Spinosad. Neem Oil is best used for preventative measures, but sucks at treating anything; and shouldn’t be used during flower. And for God’s sake don’t vacuum your plants, that’s just plain retarded.

  7. i use a lil neam oil with a lil bleach and laundry soap. seems to work great. 1 gal of water 2 tbl spoons of bleach 2 tbl sppons of laundry soap and 2 tble spoons of neam oil.

  8. Azamax works well for getting rid of spider mites. as well as the little aphids in a hydroponic setup.

  9. Neem oil works a treat iv tryed other man made chemicals and found that NEEM killed all mite now im living the dream with miteless budz cheers

  10. 1 tbls of Neem oil to 1/4 tsp of dish soap in a quart spray bottle, spray top and bottom of leaves ’till runoff, repeat in a couple days. Only thing I’ve found to kill them. Of course its much more effective if you’re able to treat when they are about a foot and smaller, I run my fingers UP the plant so that I’m lifting leaves while spraying. I’ve also found that the amount the label recommends should be about doubled for effectiveness. NOTHING comes into room without a ‘precaution spray’. Completely organic and safe also.

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