I've got spider mites, now what do I do?

Spider mites are probally the most prevalent pest to inside growers. There are many ways to erradicate these critters but can be broken down into two types of methods. These methods are chemical or organic.

With any pest erradication program where you are depending on a chemical, be it organic or synthetic, it is best to cycle between three different pesticides for optimal results and to ensure the critters don’t build an immunity to them.


I’ve found that spraying with a pyrethium based spray to be very effective. Buying one that is combined with garlic would work as a repellent to these pests as well. The only problem with this is recently there have been shown to be pyrethium resistant mites. The treatment regime with this should be at least one spray a week, but no more than two. Don’t think that more poison concentration will help remove them faster as it may only lead to your dissapointment as you see your plants suffer from burning. When spraying make sure that the underside of the leaves get just a much of a generous spraying as the tops.

If things have got right out of hand and nothing else seems to work you can count on flea bombs purchased from local supermarket. Be warned as they are full of dangerous poisons and the use of these should be greatly avoided within the last few weeks before harvest. The regime for these are one a week until problem solved, this is usually one week but occassionally you will need the second one. Make sure to turn off all exhaust fans for two hours from the time that the bomb is initially going off. After this two hour period is over turn back on exhaust fans and air out room thoroughly. Do this when the lights are out as a room full of fumes has a habit of exploding when a heat source or spark is present. These are so effective because the actually break into every part of the breeding cycle killing mites in all stages.

The recent success in mite eradication has come from the availability of a pesticide called Avid. Many growers swear that this is the only thing that really works without reinfestation. It is extremely important to kill them off completely and not start breeding resistant populations.


The most popular of the organic pesticides in recent times is neem oil or neem based products. These do work well in most cases. The treatment regime for these is no more than every three days and should be avoided in the last couple of weeks due to the fact that it can give the flowers a dirty flavour when consumed.

One completely chemical free way to eliminate mites is by manipulating the humidity in your grow room to above 80-90% for no more than three days. Any longer than this and you’re asking for mold. This works because the mites absorb the extra moisture in the air and literally explode due to absorbtion of too much water.

Another manual way to go about things is to go in every day and give the plants a liberal spraying with plain water on both tops and bottoms of leaf sufaces. This physically knocks them of and disturbs there patterns as mites may not move for three days at a time. With this, as with the previous method, beware of mold.

With any treatment using chemicals be carefull to follow instructions and follow good safety procedure. It’s not the best feeling to be stuck in bed for a day due to inhalation of chemical vapours.


Using cold water can help as well and cold temps I was informed can disrupt the breeding cycle. Cannabis can survive 45 F for longer than the mites.


They don’t breed at low temperatures, but they don’t die either. If your product isn’t subject to state testing, Abamectin or Spiromesifen are great options to kill the mite infestation permanently and change your habits to prevent reinfestation. The Vitalist-organic types will howl at the suggestion, but I’d much rather smoke trace amounts of properly-applied pesticides than mites/eggs/waste.

Transfer of mites from outddoor plants, taking in outside clones, and whiteflies are the most common vectors. Referring to the FAQ post, mites laugh at pyrethrin, though you’ll likely have success with the later-generation pyrethroids.


I went a round with Avid months ago. They laughed at it.

They don’t breed at low temperatures, but they don’t die either.

Nope but the air/a vacuum/ or a pump sprayer with cold water in it will wash them away.

The Vitalist-organic types will howl at the suggestion, but I’d much rather smoke trace amounts of properly-applied pesticides than mites/eggs/waste.

It rains in the jungle and the plants dry out and survive and the insects are washed away. I gently wash mine in a solution of peroxide and lemon water and shake gently and dry. I am not harvesting tons either :slight_smile:

@Olbrannon If Abamectin applied at normal dose didn’t work, try Spiromesifen. We talking two-spotted, russet, or broad mites? I’m genuinely surprised that Abamectin didn’t at least provide initial knock-down. Was it outdoor mites or did they come on clones? Did you apply one, or several treatments?

Washing a few bugs away won’t do anything. They’re still there, the eggs are still there. You’ll fight them forever if you don’t kill every single one. The organic types are often somehow okay with that. The jungle isn’t a grow room, kinda apples and oranges. If rain killed bug infestations, farmers would have zero use for pesticides. But it doesn’t, and they do.


The eggs are in the leaves and you would be right. …I have a plan. Summer and high humidity will be here. I can put everything in veg and run 80-90% for a month if I want.

Method-1 PPS is supposed to be organic friendly, i think its just essential oils with isopropyl alcohol or something, but it was fairly ineffective at combating thrips … i wouldn’t rely on humidity and temperature alone to take out a spider mite infestation though :confused: if you really don’t like pesticides you should just trash everything and start over


I have a sprayer and some horticultural oil. Also neem. Been cleaning and removing affected plant material and areas and spraying with neem oil and or just cold water at times. Right now humidity is high and they aren’t exploding like they can/will if unchecked in good flowering conditions.

I’ve also applied Captain Jacks Deadbug and 3 in 1 insecticidal soap at different times. At the moment things are alright Gonna spray with the hort oil next day or two.


Anyone know how to kill these things?

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By using some strong chemical shit multiple times. There are other methods though that will keep them at bay somebody here lately used sulphur powder but doesn’t go down well in the weed flavour.

Burn your house down and start over from scratch.


Been fighting mine with a hard spray every 3 days, followed 5 hours later by a rinse with fresh water . Using Spinosad, and just about have it contained. Have not seen anymore leaf damage since I started, and caught it early enough to have never seen webs nor had a full on infection. I seem to be staying ahead of them, and the plants have not suffered much at all. I will keep using it through 6 or 7 weeks of flower, the 3 -4 weeks will just be water blasts every 3 days.

Seems the cold water from my sprayer does a really good job of knocking them down. They are so lazy they will sometimes NOT MOVE for 2-3 days. Then the Monterey spray has a chance.

I start with the sprayer UNDER the plants and completely soak the undersides with my long wand. Do all the plants that way, and their pots too. Raining from the underside of all the leaf’s. Let it sit 20 minutes, THEN completely soak the plant from the topside. This seems to get a huge majority of the live bastards. Regardless of what is written, Spinosad DOES NOT seem to kill their eggs. WHY I do an every 3 day hit.

Will my spiders become immune to it…NO…come on, will take generations and generations.

The fresh water wash seems to work well. Do it 2 hours before lights out, and have a big ass oscillating fan blowing on them so at nighty night time they are 100% dry.

IS it ideal, lol, NO, but gotta do what ya gotta do! The plants seem to be getting use to it, and taking it in stride. They LOVE the fresh water rinse, and will pray till lights out .

I am not sure IF I can get rid of them in the flower room 100% BUT I CAN contain them, keep their #'s way way down, and not let them breath long enough to FUBAR my run!!!

I hate these lil bastage’s, truly do. Ran for years without any, took a cut recently and …y’all know the rest. 100% my fault…but I am dealing with it.

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Alot of misinformation when talking about mites. If ur a commercial grower trying to handle it get ur hands on avid, floramite, hexagon, and forbid. Rotate em every 3 days with a different pesticide. Dont try any organic shit and neem oil has proven to not work with mites. Dont play with em kill em early. I’d actually use those 4 products as a preventative up until week 2 of flower

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I use this when my girls are in veg…

“Pest control:
Diatomite is of value as an insecticide, because of its abrasive and physico-sorptive properties. The fine powder adsorbs lipids from the waxy outer layer of the exoskeletons of many species of insects; this layer acts as a barrier that resists the loss of water vapour from the insect’s body. Damaging the layer increases the evaporation of water from their bodies, so that they dehydrate, often fatally.”

I lived in shithole apartment, like, 15’ish years ago…neighbour had bedbugs…ultimately, I got bedbugs…$3000 heat treatment was out…$500 chemical treatment was out…got 2 bottles of this diatomaceous earth and dusted it EVERYWHERE!!!..every nook and cranny of the couch, bed, every corner of every room, along all the baseboards, into all the electrical outlets (this is how I assume they got I to my apartment)…everywhere!!! Cleaned it all up 7 days later…NO BEDBUGS!! Never had an issue after that.

Lightly dust the plants with it (it’ll look like they came out of a coke party). Leave it on for a few days and then rinse or dunk clean with fresh warm water. Repeat as needed.…probably won’t need to do it again, as long as all the eggs hatch before you rinse.


Floromite and Oberon 4f works g great. My mites laughed at spinosad


only had mites indoor once i treated with off the shelf with traditional products made for edibles. Never seen em since but our climate is coldish and tempo

Excuse text modification

Listen to this guy. He speaks truth.

Don’t cover your plants in diatomaceous earth or waste time with organic remedies that will frustrate your mites but not kill them. Do it right the first time, use what the pros use. If diatomaceous earth worked, every greenhouse in America would use it, since DE is so cheap, it is practically free.

Referring to the other guy, if you ever get bedbugs for the love of god don’t use DE. It DOES NOT WORK. You will still have bedbugs and a huge mess to clean up. Use professional products, and do it yourself.

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HEY EVERYONE i just had mites this grow i used Cultured biologix mercenary it’s an all natural blend of essential oils

I was skeptical at first but it actually works i sprayed daily for about a week cleaned my tent and slowly backed off. I had zero negative effects and the mites are gone. I also defoliated and had a fan blowing under the the canopy to make it too windy for them to be comfortable got some wind burn on lower popcorn nugs but no mites.

I also only had one plant so i can’t speak for an infestation with numerous plants

I figured I’d leave this bit of info for people like myself not wanting to use chemicals


I had mites in this lol ended up cutting them since they were in week 6 of flower and couldn’t use Floromite or Oberon aka forbid. Cut everything but 2 seedlings sprayed room and tent in Floromite then a week later with Oberon. Got 2 clones from a friend saw mite damage in 4 days sprayed them with Oberon and they are happily mite free now.