What do you use for pest management?

What do you use for preventative pest management? What pests have you encountered and how did you deal with them? What products worked well and which didn’t work so well?

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I have fly strips hanging from poles and lights. I also use a spray leaves, where I add Neutralizer (growsolutions.com) a natural plant wash it is a natural sufactant and neem oil. I add to topsoil around stalks old coffee grounds with Cayanne pepper mixed in as a deterrent…


Sounds like a good setup @espx. Has it worked out pretty well for you so far?

A lot of people don’t like this but if you use neem oil spray on the plants, it really does reduce getting mites. Also I love lady bugs but have never used them in a grow this size.


yes it does work for me of course you have to keep your rooms spotless clean I mop floor with soap n bleach weekly,
make sure containers or clean wipe with bleach water, in hydro I clean with concentrated peroxide 30% (C2h2o) rubber gloves required but in soils just use bleach n water on outside of containers.


Ohhh, pesticides. Let’s see here. I am going to lump fungicides in to this as well, as it is all managed under the same umbrella.

In commercial cannabis production, you need to be prepared for EVERYTHING. If you see it at all in a small garden, you will see it amplified many times over in a commercial setting. That being said, the most common problems I have run in to are (mostly in the order even):

Powdery Mildew
Spider Mites
Russet Mites
Cyclamen Mites

Powdery mildew is by far the biggest problem I have ran in to in commercial production.

I always recommend a systemic approach to pest management and its seems to be successful in my experience.
Step one is control and addressing the root cause. Eliminate the immediate problem that is causing economical loss greater than the cost of treatment.

For powdery mildew, you need to monitor you environmental data carefully. The primary causes of powdery mildew is improper air circulation, improper humidity control and improper temperature control. Mites often spread significantly faster under improper environmental conditions as well, high humidity, large fluctuations in temperature and stagnant air cause mite populations to explode quickly. Letting humidity get too LOW with powdery mildew and it spreads spores faster and further. It’s all about environmental control. Get your humidity in check. Get you temperatures in check, ensure your air is moving and exchanging. Get environmental data loggers to monitor humidity and temperatures over 48 hour chunks, look for spikes and variations.

Once environmental are addressed and dialed, move on to control. If you try to control with bad environmentals, you are going to keep re-introducing your problems to your plants. It’s a losing battle. For dehumidification, every pint of water you give to the plants is a pint of water that will have to be removed from the air. Size your equipment accordingly. Ideal-air, Quest for smaller rooms, Surna for medium rooms and Subcooled for large rooms. DO NOT UNDERESTIMATE THE IMPORTANCE OF HUMIDITY CONTROL! For HVAC, one 1000W DE fixture needs about 4,500 BTU of cooling. Again, size accordingly.

Control. For powdery mildew and mites, I will swear by BioSafe Systems. Their 4 products, when used properly, prevents and treats mildew and mites. ZeroTol is a Hydrogen Dioxide/Peracetic acid combo that is amazing. It is extremely gentle on plants, can be used on cuttings and bare roots, and it annihilates PM/botrytis/pythium and most bugs on contact. AzaGuard is the strongest Azadirachtin concentrate in liquid form that is out there. The cost per treatment is the lowest and its efficacy is higher than other similar products. This stuff kills bugs. OxiPhos is a systemic fungicide that works incredibly well on powdery mildew, it has a different mode of action than ZeroTol and is approved for most food production and is approved for use in most Cannabis production laws around the country (as opposed to myclobutanil!) Lastly is TerraGrow, which is a beneficial bacterial inoculate that works to out-compete and prevent bugs and spores from forming on the plant to begin with. All these can be used as foliar treatments OR soil treatments

Check out the PDF I attached. biosafe_systems_crop_protection_guide (8).pdf (214.8 KB)
It is a Crop Protection Guide that is specifically made for cannabis production and it WORKS. If you are having problems, just start using that program and it WILL help. I have personally implemented this in several Tier 3 operations in Washington State as well as several medical grows in AZ and CA, among other places.

Fore sever mite problems, I will steer people towards a rotating application of pyrethrins and azadirachtin, usually AzaGuard and Evergreen. I would always add a wetting agent, such as SM-90 to help spreading and coverage, which greatly increase effectiveness. I tell people to hit them hard, with the curative rates listed on the bottles. Day 0 you can start with Evergreen OR AzaGuard, then 3 days later spray with the one you DIDN’T use (Day 0 = AzaGuard, Day 3 = Evergreen, Day 6 = Azaguard, etc, etc.) Do this every 3 days for 2 weeks (roughly) or until you see significant control happening. Once the bug population starts to get under control, I switch to once weekly applications of a tank mixture of BOTH at the maintenance application rates (all rates on on the labels.) This is a deviation from the “crop protection schedule” but is essentially what they are having you do. Rotate classes of treatment agent and time it to kill multiple life cycles of bugs before they reproduce.

Read up on the bugs you are targeting, understand their life cycle and time the applications to coincide with their reproduction. Some bugs have a 48 period from hatching to laying eggs, if you don’t hit them in that window, you will have another generation of bugs to deal with as most products don’t kill the eggs.

The final things to really address is EXCLUSION of pests from the growing environment all together. I always caution large operations about bringing in ANY plant material to their operations. I, personally, start large operations with sterilized seeds (treated with a fungicide) and NEVER bring in vegetative cuttings. However, if you are gong to bring in vegetative plants, then you need to ensure they are VERY clean. Quarantine them off site, create a standard operating procedure for sterilizing them (thorough treatment and evaluation over weeks) and bring them in with no soil if possible.) In addition to the plants, the PEOPLE need to be clean, too. Put foot baths at the entrance to every grow room. Have growers change clothes frequently and provide clothing that you KNOW is clean and sanitized to your workers. Have them wear gloves, hair nets, shoe covers (or provide shoes that do not leave the grow house and can be sanitized, this is recommended.) Provide alcohol spray bottles to trimmers and people that are pruning to clean their hands and trimmers in between each plant. Incorporate an integrated pest management program and follow it carefully. Air curtains, positive pressure, etc, all smaller things that can go a long way in preventing problems.

Oh, I don’t want to forget a part that is important to me, and that is PPE. Provide proper protective gear to your workers. Full coverage, water-proof suits, long, compatible gloves, respirators with properly rated filters and pre-filters, goggles, etc.

There are a million problems growers can run ito when going commercial, but with the right planning, the right equipment and the right plan, you can avoid many of those issues!


I’m not an expert grower yet, so for me I try to mitigate my risk. I lean heavily on prevention starting with gloves, mask, disposable coveralls. Any new plant goes through a 4 week quarantine. The best prevention is a system that maintains optimum room temperature, air movement, and humidity. I prefer a sealed room environment, as it allows you to reduce your risk to outside threats.

I use inline UV sterilization lights with my Carbon Filter Fans. It helps scrub and clean the grow rooms internal air. UVC light can also be used to combat Powdery Mildew, and is one of the cleanest and quickest ways to kill PM spores. An understanding of UV light and safety precautions is needed before attempting this though.

I’m a small scale grower, and totally open to suggestions and learning new techniques. I plan to grow my operation steadily so learning what larger facilities do when they scale up is very interesting. I really enjoyed the recent posts. Thanks for sharing guys.


@casey Great post! You mentioned a sweet spot for humidity, is there an RH you like to get close to?

@garymorgan How do you quarantine your new plants? I imagine there’s many methods to do so.

I’m assuming that requires eye protection while the UV lighting is on? How long do you use the UVC light for and on what schedule?

If you want to read a little more on UVC, this is a pretty good link from THC Farmer Forum

There is a light you can buy at Growershouse and other hydro retailers. Here is the link;
or you can build your own, if your a DIY guy like me. :slight_smile:
There’s a calculation based on UVC light wattage, distance to the plant and the amount of time you expose your plant. It’s important to wear UV sunglasses and not have any exposed skin. The Clean Light is a patented design that uses a 36 watt hand held lamp that you hand deliver uvc light to each plant sweeping around the plant each day. I’m going to be doing some testing with UVC light using some DIY lights. I want to place several on the underside of my canopy and some on top of the canopy. I’m thinking of having a a daily 10 second dosing each day. It would be nice to have them on light movers, we’ll see.


Thanks for the in-depth answer. Yeah doing it by hand seems rather labor intensive so I’ll be interested to see your setup once you get it up and running.

Hey Hunter. I’m not sure if you were asking me or @Casey your questions.

My Quarantine methods are fairly basic. I have a separate room (personal grow) that I keep any new plants in. Mine happens to be my laundry room :slight_smile: I like to keep the new plants or cuttings in this room for up to 4 weeks. I watch the plants closely the first couple weeks, and mostly look for any signs of pests, or disease. It’s nothing fancy, but it gives me time to see if the new plants have any problems before I introduce them to the rest of my plants. I’d say most plants spend three weeks at a minimum. In that time if there’s a problem you should be able to see the signs.

For humidity I like to keep my veg room at around 60%RH. I think the ideal Bloom RH range should be 52%-57% with optimal being around 54%-55%.


We take a bit of a different approach to growing cannabis at our “pot plant”. We use predatory mites and NEVER EVER ANY PESTICIDES. Our grow is definitely not operated as a “clean room”. My dog is always with me, no one wears designated shoes or clothing and street clothing is fine with us. We have very little in the way of HVAC and our heat control is a huge exhaust fan that I bought off of Craigslist for $250 that evacuates 23,000 cubic feet of hot air per minute and we have multiple intake fans bringing in cool air around the space. Even with that we cannot grow inside if the outdoor temps are above 60 degrees. Luckily for us we chose what we think is the very best spot in WA state for outdoor growing and from our 3 outdoor harvests we believe our choice was spot on.

At first we tried the ultra clean environment thing and it just was too labor intensive for us. We went to predatory mites in November of 2014 and have not looked back or regretted that choice for even one second. We sent some of our outdoor product for intensive pesticide testing, mycotoxins and heavy metal testing with the one lab in the state that does the most intricate testing available here in WA because even though we know we don’t use any chemicals on our plants, you never know what is already in the soil or what could come in on your plants from wind from surrounding land. The report we got back said that we were one of only 2 farms in the state that tested so clean:-) Our indoor flower tested the same. We have learned a lot about pest control over the past 2 years and I am happy to share any knowledge I have in that regard with anyone that is interested.

Our first battle with spider mites was horrible. We thought we were doomed…we destroyed a bunch of plants that we should have saved but it was a huge learning curve for us. Luckily a guy that sells predatory mites contacted me and we tried it out. For the first couple of weeks I thought he was just jerking us around because we did not see immediate results but within 3 weeks there was way less damage from spider mites and within 5 weeks we really saw very little damage at all. From then on we have not sprayed one single thing on our plants other than water and foliar feeding. Outside we have no pest issues at all, most likely because it is so windy here the little bastards can’t hang on:-)


That’s great to hear! I’ve always been a fan of taking strategies from nature. Cannabis can grow in the wild, and that’s because there’s a whole ecosystem.

That’s a very interesting grow operation you have! I love that every grower has his or her own way of doing things. There’s no right or wrong way as long as it works. I hear from other consultants that every grow operation is different…With all the variety of methods out there it means we can all find a way to grow that suits our style. Keep up the good work Susy I’m glad you’ve joined up. I look forward to hearing more about your operation and experiences.


That was great ….so useful and important, should be S.O.P. for all growers.

Thank you for the knowledge!


I would love to hear more about your mites and natural solutions, do you have any more info online or to send?
I especially want a solution to the caterpillar issue I get down here in Southern California, any real working solutions appreciated.



For outdoor and open greenhouse we facilitate wasps and hornets as part of our caterpillar control team. We feed them with certain companion plants and leave any nests we find (which can be interesting when they decide to setup in your greenhouse). They are amazing - I found a hornets nest (mud) under a pot I moved and it had 23 little green caterpillars in it. All waiting to be eaten by the next generation.

Diatomaceous earth can also be useful against soft bodies insects such as caterpillars - depending on the environment and application.

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Diatomaceous earth ! I have never heard of it —easy to get? apply how?, any usage directions… I am always learning…

and how much WASP acttivity was there?, All i ever got was stung, I had no idea they ATE catapillars


Diatamaceous earth is made up of the skeletons of diatoms, little ocean critters. It’s microscopic “dirt” that’s jagged and rough on insect exoskeletons, but harmless to most other animals. You can sprinkle it on like a powder, or dump it like dirt.