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What are Pesticides?
Pesticides are defined as chemical or biological preparations that are designed to control, repel, and/or mitigate a pest.
Pests can include:
Pesticides can come in many varieties and are usually defined by the type of pest they control and their mechanism of action. For more details, click the accordion below.
- Biological or Chemical
- Some pesticides are considered biopesticides because they incorporate elements from living organisms or are living organisms themselves. These can include naturally occurring substances like the essential oils, microorganisms that control pest populations, and/or genetic substances that have been introduced into a plant’s genome to protect it.
- Chemical pesticides are generally synthetic (manmade) or are a chemical derivative of a naturally occurring product.
- Mechanism of Action
- Some pesticides work by interfering with the nervous system of an animal pest.
- Some pesticides work by disrupting enzymes essential to the metabolism of a plant or animal.
- Some pesticides work due to their toxicity to certain organisms.
- Some have unique mechanisms by altering the life cycle of the target organisms. This can include defoliants, desiccants, insect growth regulators (IGRs), and plant growth regulators (PGRs). IGRs and PGRs use hormones to control their targets.
- Biodegradable or not
- Relatively self-explanatory, but some pesticides can persist in the environment for long periods of time (like DDT), whereas others can degrade.
- Type of Pest they Control
- Most pesticides are specific to a certain class of pest. These can include mites, algae, various microorganisms, nematodes, mollusks, rodents, insects, mollusks, weeds, fungi, and more.
- Most have -cide as a suffix in their name, which means “to kill.” Fungicides, for example, are meant to “kill” or otherwise control fungus. Rodenticides kill rodents, miticides kill mites, etc.
Washington State Department of Agriculture (WSDA)
The program I’m in do pesticides/fertilizer registration. We also have folks that do licensing for growers, commercial applicators, pesticide dealers, consultants, and so forth. And then in other programs, we have people who do compliance investigations that follow up on alleged misuse of pesticides. We have a technical services program that is involved in education and training, especially for farm workers, but also for others as well. We also have a waste pesticide disposal program. Additionally, we have a specialist who deals with chemigation and fertigation, which is the application of either pesticides or fertilizers through irrigation systems.
Generally speaking, there are more rules dealing with pesticides than those that deal with fertilizers, but there are still a fair number of rules involving fertilizers as well. Like I say, the overall goal is to keep it safe and legal.
However, California’s pesticide regulation is not done by their department of agriculture. The California Department of Food and Agriculture has a lot of responsibilities, but pesticide regulation is not one of them. In California, it’s the California Department of Pesticide Regulation. In Alaska, it’s part of the department of environmental conservation, so it really depends on how the statutes are structured in a given state as to where the responsibility for pesticides and fertilizers will be. Fertilizers are almost always with the departments of agriculture whereas pesticides are sometimes the department of agriculture or sometimes with another agency.
I think in broad terms, we’re similar to a lot of other states departments of agriculture, but the details are going to vary state by state based on their statutes.
There’s a number of areas we work pretty hard in. The waste pesticide collection program, part of technical services, does a very nice job. They collected over 3 million pounds of unusable pesticides, which they appropriately disposed of. There’s folks who do hands-on training for farm workers that do some very good work. Our organic program is very well-thought-of nationally. We’ve got some really good folks in a number of programs. Those are several examples.
Pesticide registration really depends on the type of pesticide you’re talking about. If it’s a federally registered pesticide and it’s not a new active ingredient, the review process is fairly simple. We basically look to make sure that we have the information we need; the pesticide has a legal use and the application is complete. If it’s a new active ingredient, we’re going to want a little more information to see if there’s any specific issues we need to be concerned with.
When it’s a more specific type of pesticide that requires additional review, which is known as a section 24c registration or a section 18 emergency exemption from registration, then we require quite a bit of data.
If somebody makes a new active ingredient, they would need to start by registering with the EPA. And once they’re done with the EPA, then they need to start talking with the states where they’re intending to distribute the product. If it’s something that’s going to be labeled for citrus or cotton, they’re probably not going to bother with Washington. On the other hand, if they’re interested in weed or apples, they’re probably going to push for Washington.
Editor’s Note: You can search through EPA dockets at regulations.gov
One of the things that we require testing for is the metals, specifically certain heavy metals and their concentration in fertilizers. We work in conjunction with our Department of Ecology in addition to other agencies if there’s something they can help us out with. Virtually everything to do with fertilizers is regulated at the state level. States have developed their own processes and we work cooperatively with other states on both pesticide and fertilizer issues.
Additionally, we participate in a number of organizations that deal with both pesticides and fertilizers. We meet periodically with other state lead agencies and in the case of pesticides, we meet with the EPA, both the regional office here in Seattle and we occasionally go to DC for meetings.”
Generally our penalty matrix, at least as far as I understand it, is designed in such a way that a first offense will result in a warning or relatively minor penalty unless it’s a very serious issue. If it’s a repeat offense it’s going to get more and more serious. Over time the penalties will ratchet up if you’re a frequent customer, so to speak.
We’ve been working with them for about three and a half years now I think. We recently signed an agreement that our chemical lab in Yakima in eastern Washington will do testing for the Liquor and Cannabis board. They agreed to buy a couple pieces of equipment and hire a couple of employees, and we agreed to do the testing. It’s a new agreement, so it isn’t going to kick in until January… but I think that’s going to hopefully reduce the potential for folks to use pesticides that they shouldn’t really be using.
Cannabis and Pesticides
It really isn’t a lot different than growing tomatoes, other than the Feds might have a slight problem with it. Erik Johansen
We don’t make recommendations for any pesticide over another. When we register products, we provide that information to WSU because they’re our state land grant. They make that information available on a public database (PICOL) and for the cannabis growers.
Since there very few pesticides that are specifically labeled for use on cannabis, we have developed a list so they have guidance on what’s allowed for use on cannabis. That relates back to both the rules from the Liquor and Cannabis board which is the state lead agency for cannabis regulation. The Department of Health is involved in regulation of what they term “compliant” products, which most people refer to as medical marijuana (MMJ). Our list is used by both those agencies and we’re also in the process of working out a process of doing the same thing for hemp for the Department of Agriculture.
Editor’s Note: Washington defines the cutoff between cannabis and hemp as being 0.3% THC, with hemp having less than that amount present.
However, there’s a huge difference if you want to look at apples or potatoes or wheat. Most major crops here have between 1200 and 1500 pesticide products available for use. Cannabis, on the other hand, has about 330 products available. It’s increasing steadily, but not to the scale of other crops.
As a result, the tool set that you have to work with is vastly different if you’re a cannabis grower. Cannabis can only use tolerance exempt or minimal risk products. Thus, cannabis is a very high-value crop with extremely limited tools. We’ve got around 80 or so active ingredients, many of which are soaps or essential oils. This restricts a whole lot of potential ingredients, some of which would be well-suited to the application.
There is a strong emphasis in the cannabis industry on pesticide-free or as low-input as possible. Given the limits on what’s available, that’s a pretty reasonable approach. The problem with that approach is that pests don’t care if it’s conventionally grown or organically grown. If you don’t have the normal tools to work with, you had better be very good at what you’re doing. You need to scout constantly, use beneficials. sanitize the area, and quarantine new plants. Be sure that you’re not bringing something else in that you don’t want. If you’re growing with limited pesticides, then you have to rely on other tactics pretty heavily.
Organic methods, just to be clear, are not pesticide free. There are quite a few pesticides approved for use in organic agriculture. About a third of the pesticides that are on the allowed list are approved for organic agriculture. If somebody wants to grow “organic” cannabis, they could use organically allowed materials, pesticides, and fertilizers that meet the criteria. Organic certification for cannabis doesn’t exist yet, but they could grow it that way.
Turn the question around. If you’re not practicing IPM, and you’re trying to grow cannabis, the odds of failure are 100% or something close to it. Integrated Pest Management is a holistic kind of approach, using all control tactics, including sanitation, exclusion, beneficials, and even pesticides too. IPM does not mean pesticide-free. IPM means using appropriate pesticides at the appropriate time at the appropriate rate, as needed and not prophylactically.
If you’re not practicing IPM, and you’re trying to grow cannabis, the odds of failure are 100% or something close to it. Erik Johansen
Given the tools available to cannabis growers, IPM is essential. There’s some consultants that help some of the cannabis growers here with IPM. If you’re not practicing sanitation, if you’re not checking the plants coming in, if you’re not working with beneficials and if you’re not using pesticides correctly at the right time, good luck. You really should be monitoring or working with somebody who’s helping you monitor what’s going on at your grow. Monitor, monitor, monitor.
Unfortunately some of the pests that the cannabis growers are dealing with are tiny little mites. You need a high-powered lens to see the stupid things. A variety of companies have predatory mites, which I think could be incredibly useful. There aren’t great miticides for growers to work with, so having predatory mites that you’re releasing periodically can keep the number of mites under control.
One of the difficulties we have in Washington, with the exception of the organic department, is that we do not look at soil amendments. The ODA does and the Idaho Department of Ag does. Sadly it’s not part of our statutory legislation.
When we talk about tolerances, we’re talking about the amount of residue that’s allowed to remain on a crop at the time of harvest for food or feed commodities. So if it’s going to be fed to humans or animals, there needs to be a tolerance level for the pesticide. Alternatively a pesticide can have what’s known as a tolerance exemption. Tolerance exemptions have no limit on the amount of residue at the time of harvest because the EPA is not concerned with the toxicity of that particular compound.
There are some pesticides that are exempt from tolerance that we believe are allowed for use on cannabis. If a pesticide requires establishment of a tolerance, it cannot be used on cannabis. Things that are exempt from tolerance include old products like sulfur dust or BT (Bacillus thuringiensis), where there’s a long knowledge the product and there isn’t a toxic concern with the residue. That’s kind of an important consideration, because in Washington, we definitely consider cannabis to be a food commodity. It’s both smoked and consumed.
Editor’s Note: Tolerances and tolerance exemptions can be found under Title 40 – CFR – Part 180. Specific Tolerances are in subpart C, while tolerance exemptions are in subpart D. CFR stands for “Code of Federal Regulations.” Title 40 deals with protection of the environment, and Part 180 deals specifically with tolerances and exemptions.
The cannabis industry is considering the formation of a Cannabis Commission. We have about 22 commodity commissions here in Washington. Tree fruits, berries, grain crops, potatoes, etc. Most of the major crops have a commission. Well, cannabis is a major crop in Washington and it has very little support, very little research, and no good mechanism right now to do research. The Liquor and Cannabis board has been working on implementing a cannabis research license, but it’s not there yet.
Do you want to make a commission? Are the majority of growers on board with it? If you are, file a petition with us. We’ll go through the process. It’s an industry decision, so it’s not our place to do it for you or not. But to be clear, pretty much any other commodity of this size has a commission, and there’s a reason for that.
CannaCon is an annual grower meeting, which has been held either in Tacoma or Seattle. They have some very good education there, and I’ve done outreach in the first three, and intend to do some next year if they want me back.
Growers Network Member Questions
We need to treat this as a real business, a real crop, and act like adults.Erik Johansen
The disadvantage is that these products only have some pesticidal activity. They have some value, but you’re not going to control all your pests with minimum risk pesticides. I think that’s wishful thinking at best. I’m not here to badmouth people, but anybody who believes that these products are going to solve all their problems — I’ve got a bridge to sell them. Part of it is going to depend on what you’re trying to accomplish. What is the pest?
If you have a question, call us. The list of compliant pesticides is actually available in two places. If all you want is the list, you can go to the department of Agriculture website. There’s a PDF copy posted there which you can download. The other place you can get the list is from what’s known as the pesticide information center online, or PICOL database at Washington State University. That website allows you to search. If you just want to look at products that are labeled for mite control or just mildew or just organically approved pesticides, whatever, you can narrow your search down.
As a note, our list contains both commercial and homeowner products because there’s a provision for personal grows under certain conditions. Some homeowner products can also be used by commercial growers, but some of them can’t. You need to look at the label closely to make sure it’s really suitable for what you’re doing.
Editor’s Note: The PICOL website is somewhat difficult to use at first. There are tutorials available on how to use it.
The difference between the other three is that a pesticide is something that is claiming to control, repel, or mitigate a pest, which doesn’t just mean insecticide. It could be an herbicide, a fungicide, a rodenticide, or a miticide. That means anything with -cide in the name, whether federally registered or not. We include spray adjuvants in this, which also means things like surfactants which aid to the application or effect of a pesticide.
There are things called soil amendments and crop production aids, some of which are absolutely valid products. These are things that you use to amend the soil to make it drain better or make it hold more water. As long as a company’s not trying to sneak in a pesticide or a fertilizer and calling it something else, we’re fine with that.
With foliar sprays/leaf shines, there is no valid use in cannabis at all, and it’s basically snake oil. I’ve seen some companies who have a Neem oil product listed as a leaf polish. Take a look at the label some time on one of those and tell me that it looks any different from a pesticide that contains Neem Oil. But it doesn’t have proper worker protection standard language or proper restricted entry interval/pre harvest interval.
Frankly the industry needs to stop trying to be cute. This practice of “We’re going to try to get around the rules by calling it something it’s not or sneaking in something and not declaring it…” It needs to stop. We need to treat this as a real business, a real crop, and act like adults.
There are a few allowable PGR’s on our list of allowed pesticides. Things like indole-3-butyric acid or IBA are allowed to be used as rooting hormones on cannabis. If you want to take cuttings and root them, you’re cool as long as you’re using one of the PGR’s on the allowed list. There’s some other PGR’s that are allowed as well.
However, there’s quite a few PGR’s, things like paclobutrazol or daminozide or chlormequat that are not allowed. In fact several of them are only allowed for use on ornamentals. Well cannabis may be a pretty plant, but it’s not an ornamental. It’s going to be consumed.
We treat PGR’s the same as we treat pesticides. There is one odd exception, and it’s what’s known as a vitamin hormone exempt product. And that is one exemption from the federal registration requirements for PGRs. One of the requirements for that exemption, however, is that the plant is for ornamental use only. You’re growing cannabis to consume it, so you can’t apply a vitamin hormone exempt product.
If you don’t understand what the laws, rules, and exceptions are, you need to talk to somebody that does. It’s going to be someone in the state lead agency in whatever state you’re working.
Seriously though, we’ve worked closely with Colorado Department of Agriculture and they’ve been really good to work with. Both Colorado and Washington started with a similar approach.
Oregon came online afterwards and I think they’ve adopted a fairly similar approach. They also have had some of their own interesting ideas which we’ve since incorporated into our criteria. Alaska was next and they’re also taking a very similar approach.
I would say that the model that was initially developed by Colorado and Washington, or rather, Washington and Colorado, is a good place to start. Every state since has put their own twist on it. I’m sure that California will be developing some additional guidance and already have some nice guidance documents regarding pesticide use.
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- Want to learn more about WSDA pesticide regulations? Check out their page on pesticides and marijuana!
- Want to learn about pesticides safety regulations for workers? The WSDA recently released a helpful PDF about safety.
- Looking to learn about chemigation or fertigation? The WSDA has put out a helpful guide about fertigation.
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About the Author
Hunter Wilson is a community builder with Growers Network. He graduated from the University of Arizona in 2011 with a Masters in Teaching and in 2007 with a Bachelors in Biology.