Grower Talk: Managing Pests Before They Arrive

Welcome to the first entry in a new series here on Redheaded Blackbelt, Grower Talk. Cannabis growers are invited to submit informative articles talking about issues and concerns unique to their culture and industry.


This season, let’s hope this is the closest you come to a plant that looks like this bad.

Below, an anonymous grower talks pest management.

Last year my garden suffered from one of the most devastating pests known to cannabis farmers: hemp russet mites. I managed to reap a meager harvest and over the winter months I spent at the library researching this pest in particular and pest management in general. I hope to apply what I have learned and hopefully my harvest will reward me for my diligence. Meanwhile, I would like to share a few tips that I picked up so that you will not have to endure the suffering that I went through this past year.

First of all, Integrated Pest Management (IPM) is a method of controlling pests before they get out of control. The founding principle is that the better you are at detecting and preventing problems early on, the less you will need to rely on pesticides later in the season. The first step in pest prevention is starting with healthy, pest-free, disease resistant plants. I know how easy it is to pick up a few trays of spider-mite infested OG clones from your neighbor but I beg you not to do it. These plants will require pesticides from the moment you bring them home. Perhaps the use of pesticides doesn’t bother you but consider their cost and the time it takes to apply them, all season. Growing from seed, buying clones from a trusted source of clean and strong genetics and/or growing strains that are pest and disease resistant are the best way for you to prevent pest problems later in the season.

The second step of IPM is monitoring. You can monitor the presence of pests in your greenhouse by setting out sticky traps, both the yellow cards that hang and sticky tape that you can wrap around plant stems or pots. Check these sticky devices regularly and record what you find. Are you seeing an increase or decrease in a particular kind of pest? Are there areas of your greenhouse where you are detecting more of this pest than in other regions? You would be wise to also invest in a microscope that magnifies up to 120x. You can use this microscope to investigate sticky cards or you can select plant material to inspect. This might sound like overkill but Russet mites and broad mites are both microscopic in size. The only way to detect them early is by inspecting samples through a microscope.

The third step of IPM is called “Cultural practices.” This includes keeping your greenhouse tidy, dry and well ventilated. Over watering and over fertilizing attract pests such as fungus gnats and aphids. Also, if you notice a problem, remove the specimen as soon as possible. I know how tempting it can be to hold on to plants with the hopes that they will become healthy again but part of keeping your plants clean and healthy includes isolating those plants that can and will infect all of the rest of your plants. As far as greenhouses go, cleanliness is a virtue.

The fourth step is bolstering the immune system of your plants. Think about the human body. If a person eats a diet that is rich in vitamins and minerals, they drink lots of water and breath fresh air, they are much less likely to get sick. Their immune system is robust enough to fight off disease. The same goes for your plants. If they are healthy and have a strong immune system, they are less susceptible to pests and disease. In addition to a balanced feeding regimen, kelp, nettles, spirulina, mullein and horse tail are all rich in minerals which help plants sustain their health through stressful situations such as during transplanting and transitioning into flowering. Keeping your plants well ventilated and appropriately watered also helps plants stay healthy and strong.

Over the course of the season, if you notice a problem arising, first try a mild and organic solution. In my reading about russet and broad mites, early applications of sulfur were the most highly recommended solution. Essential oil sprays, pyrethrum and neem oil can all be very effective if used early on. The problem with using synthetic pesticides, aside from the harm they cause our bodies and the planet, is that pests will develop a resistance to them. If you catch pests early you should be able to manage your problem with a minimal amount of organic solutions.

Finally I want to mention inter-planting. Not all plants are ideal to mix in with your medicinal garden. Last year I mixed in tomatoes, peppers, cucumbers and zucchini. However, when I realized that I had a pest problem it occurred to me that the plants that I had interplanted were both harboring pests and potentially attracting them. I deeply regretted mixing my vegetable and medicine garden as I ripped out my tomatoes. This year I plan on inter-planting my garden again but with plants that are known pest detergents such as garlic, marigolds and pyrethrum daisies. I will plant my fruits and vegetables in their own beds where I will not be as concerned about the presence of pests.

I hope this summary of what I learned this winter will help you think about your own pest management plan. The key is to be ready, with information and organic solutions, for when the pests arrive. For most of us the question is not whether or not they are coming it is a question of when and how we chose to manage them. Good luck out there!

for more information on IPM please see Statewide Integrated Pest Management Program:



  • I’m pretty much of a clod in the garden, but I have found compost to be a cure-all. Any time a plant starts looking sickly, any kind — medicine, roses, vegetables, whatever — I dump lots of straight compost on them and the problem — whatever it was — goes away. Even aphid infestations… that thing where the ants turn into aphid-ranchers on your flowers. Rust. Mites. General puniness. Works like gangbusters every time. It never burnt out any plant on me either. Just heaps of compost. Water as normal. Problem solved.

    But I never ran into it in the greenhouse… so….

    • BiscuitJohansonberg

      So I am curious if you’ve noticed any noticeable taste in the finished product? I understand how inert Dr. Zymes is but that slight scent makes me a bit nervous about spraying on the flowers of the plant.

  • I’m not sure what you mean by straight compost. The compost from the compost pile and is already broken down or, the straight from the kitchen bucket. Compost straight from the kitchen bucket placed on the top soil will bring earth worms and grubs to the surface and that is good for the soil.

    • Just compost, in any shape really. I had boxes on the front deck with compost worms for the kitchen compost, that I mixed with depleted potting soil. I had a compost pile too that was curing more slowly than was seemly for the space. If you dump it on there fresh from the kitchen, it totally does attract the worms and grubs, but it doesn’t add much to the plant’s nutrient store in the short run, so if you have the start of a bad pest or a puny plant, you want compost that’s broken down enough to immediately be adding something to the plant’s roots.

      Even just dump whole bags of compost from the store if the container is big enough… or dig around and dump it in… whatever.

      It works on most problems that crop up… or that have cropped up for me… maybe not the critters in this piece…. I don’t know.

  • Compost tea isn’t gonna work on russet mites. There’s only a couple things that do and they’re not very nice. I guess until you’ve had em, you really don’t know how devastating they can be.

    • You’re RIGHT, of course, but I’ve just been plum gobsmacked by how well my simple little solution has worked on stuff I only THOUGHT needed dread toxins to cure, so I piped up about it. Might even be that the russet mites couldn’t get purchase on completely fortified plants, OR they’re doom incarnate and I’m just actually psyching my plants back into shape and only think it’s the compost, OR plain old have never ran into the really awful pests.

  • The broad and russet mites are being distributed by the wonderland nurseries in garbervillle. Buyer beware they are infested with them and God knows gown many people have bought starts from there and perpetuated the problem. I told them they had a problem with broad mites after having dirty business test a start immediately after purchase from them – they said it was part of having an outdoor nurserie—— Never go there for any reason!!!

  • nothing like compost tea will work on a broad mite they will destroy your hard work. Consider them like herpies – they can be controlled but never destroyed . Even the toxics are a huge prolonged gamble spraying in rotation ever 5 days and you are going to have a stunned damaged plant. If you get them in flower there is no chance of winning. In veg you can dunk stuff every 3 days. Best option – throw away everything and start over

    • Hemp russet mites are not at all like herpes. Just about everyone has herpes and can live a normal productive HEALTHY life. No. Russet mites are far, FAR worse than that. They are more like malaria or AIDS. The plants die from the bottom up, the flowers never fully develop, but they grow whispy, leathery, and sad looking with destroyed pistils. The little arachnids are heat-resistant, cold-resistant, sexually mature after 3-4 days, and lay in the area of 50 eggs per day. There are some non-toxic solutions, like “Nuke ’em” and “Dr. Zymes” which kill the bugs but not the eggs and are really expensive (about $100/gal). I don’t like exposing my body (while spraying) or plants to poison, so I pruined the shit out of the girls directly into a contractor bag which gets removed immediately. I spray Dr Zymes twice a week on the colas, and it has been holding them back enough for some nice hard colas to develop on some of the plants. Because they are so small, some will always evade the spray. I missed a week and they started coming back fast. When I harvest, I gently dip and roll each branch in Dr Zymes before hanging. After they are dry, I will store the dried, untrimmed buds in CO2 for s couple weeks to try and kill anything that might be left over.

  • I used to farm compost worms. I used to recondition growers’ depleted potting soil. I turned that stuff into monster magic growing soil. No science. Just went by feel, by intent alone. Almost became famous for it, but a medical disaster derailed my career as Earthworm Mamma.

    I turned boring old maroon dahlias into electric lavender monsters. The tomatoes went transcendent. The medicine thrived even on not enough sun. The people who received tubs full of my home-enhanced dirt raved about what it did for their gardens.

    Like I say, though, I have no idea what I’m talking about. I mean, I’m telling the truth, but it’s just blind luck. Basic mode of efficacy, I think, is the belief that any plant will do its best with whatever conditions prevail if they have all the nutrients it takes to do it, that they don’t just soak up too much of anything if it comes from a natural process, not a lab, not a chemical factory, and, of course, loving them.

  • Wonderland Nursery is the breeding ground for russet mite.
    Buyer beware.
    This is serious shit.


    I have heard of folks having success with a product called Nuke Em applied every 3 days. (Link above has directions for broad mite treatment) The person who told me about it does not spray for the last 4 weeks & things turned out fine. These mites are probably everywhere, cant see them with naked eye. Most likely travel on peoples clothes too. I think the mites in general are becoming resistant to treatments after sooooooo many indoor grows use poisons that are actually illegal in CA.

  • P.s. The link above also includes a well written segment on plant health that echoes whats been written here. They say too much fertilizer in the medium reduces plant health and allows for increased insect problems. They describe a seemingly good soil flush and the ppm most desirable in the water flushed. I recommend this link as a very informative read if nothing else 🙂 The product is also used for powdery white mildew & root aphids.

  • Anyone wanting the state of California recommendations for marijuana pest management (really!) email me at


    Forbid will work on them, it’s been around a few years but never made it into the mmj community where your average grower has no idea on pesticide applications and has worked to grow resistant strains of mites. It’s why floromite no longer works.
    There is another miticide on the market that works even better, but I’m not going to say it’s name because every humdum will spray and pray which will lead to more resistant species around. It just mixes with the irrigation water along with a pre harvest interval. It’s labeled for California, open field, greenhouse, and cattle feed.

    Your average humdum using Avid has no clue that one needs to tank mix an ovicide with it, because they don’t or can’t READ THE LABEL.

    • Capybara obvious

      I have spent tons of time researching and doing experiments on these broad mites—- conclusion they will damage your plants to the point that the end product is garbage. Plants will yield less, not be potent and probably get pm or hermi from the stress of the mite infestation. I tried every pesticide with ovacide at the right ph that was listed for broad mites on a rotation and even if I did kill them off the end product is still screwed. The only thing that actually worked is to heat your space up to 120/130 degrees and hold it there for 40 min. Do this two or three times over a week. It kills adults and eggs anywhere in that space. As long as plants are well established and in veg they can Handel it. If you get em again after that – take a look around outside of green house or building and see what’s making your space so attractive.

  • witness digital

    I have had GREAT success indoors with a sealed growroom and a sulphur burner ..
    I understand some greenhouse growers have used a number of these for killing pests with S02(was also used to kill anthrax at the congressional mailroom)..

    YMMV as usual
    a patient

    ps resistance is NOT a possibility with Sulfur dioxide.. you do need to have the plants dry ie not dripping with moisture, before using though so H2SO4 generation is minimal and occurs only in the pests bodies etc.. ie also kills a number of fungi and molds like powdery mildew..


    How much do you burn per cubic foot and what is the air exchange rate? Fish helps, too.

  • “Neem: Kills your plants, not your pests”

    Neem is the way the grow stores stay in business during quiet times.

  • Forbid is very effective. I used it after a 1 year battle w mites and it was a knockout win for me. Not a cheap solution but u can get a small bottle on eBay for relatively cheap. The big bottle is overkill and super expensive.

  • You wrote this informative post in the spring of 2015. With harvest season now underway, I can’t wait to hear how your garden came out this year!

  • Original GT Dragon strain from Chico CA. Is resistant to hemp russet mites. No joke they stay off of it ..
    the mites larve build resistance to all chemicals with only one spray. Do not spray same chem. Twice it builds super mites. Forbid was specifically designed to kill hemp russets.

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