Top 10 Best Organic Pesticides — Eliminate Pesky Bugs Forever!

For cannabis growers, bugs and pests are the worst nightmares. Pests tend to harm the plant in various ways — they suck vital nutrients, damage the leaves and stems, affect the plant's growth, and much more. 

However, despite the best prevention methods, you can still get pests on your cannabis plants. Most cannabis growers resort to pesticides to eliminate these bugs in such cases.

That sounds like a wise choice, right?

Not really. 

Most pesticides available in the market are chemical-based and end up harming your much-loved cannabis plants. You don’t want something that kills the plants rather than the pests. Moreover, you don’t want to consume chemical residues while using the buds. 

So, what do you do?

Use organic pesticides! Fortunately, you’ll find many organic pesticides that don’t contain harmful chemicals or compounds that may hamper your plant's growth. 

In this article, we share our favorite organic pesticides. 

Most Common Cannabis Pests

Before we start fixing the problem, we need to understand what the problem is — what kinds of pests are harmful and how?

To make it easier, familiarize yourself with the most common types of pests such as:

• Sucking pests that pull vital nutrients from the plants, affecting their growth
• Chewing pests that eat away sections of the plant at a time, including leaves, branches, and buds
• Infectious pests that spread diseases onto your cannabis culture, which can significantly affect the yield 

The most common harmful pests are spider mites, fungus, gnats, aphids, caterpillars, slugs, snails, and thrips. But there are many more. 

We also recommend you talk to the growers in our community here on Growdiaries to understand which common pests haunt your region and start preparing for those. Pests can be annoying, but they are pretty predictable.

Best Organic Pesticides for Cannabis

Once you know what pests are bothering your plants, you need suitable organic pesticides to get rid of them. Following are a few practical and harmless pesticides to use to kill pesticides on your cannabis plant.

DIY Organic Pesticides

Organic pesticides really work if you use them frequently. But, as mentioned already, prevention is better than cure. So, how about making some at home to keep the pests at bay?

The DIY pesticide approach may not work as effectively as commercial pesticides when you have a full-blown pest infestation. In such cases, using commercial products may be your only solution, especially if you're struggling to save your plants in the flowering stage. 

However, if you diligently use homemade organic pesticides at least once a week as a preventive measure, you're likely to have a smooth run.

The best part of making organic pesticides at home is that they are cheap, easy to use, and effective. You don't need a lot of ingredients to create efficient pesticides that prevent pest infestations. Most importantly, these pesticides do not contain chemicals that can harm you or your plants.

• Organic 3G spray

The 3G spray is known by many names, but it comes from the ingredients it uses — Ginger, Green chilies, Garlic — and is thereby known as the 3G organic pesticide. 

3G is prevalent in many forums among members who use organic methods to grow various vegetables and fruits. So, naturally, you can use it for cannabis as well. From personal experience, we can tell you that this pesticide works effectively to prevent and kill sap-sucking insects, including aphids, spider mites, mealybugs, and many more.

Ingredients

Green chilies ‒ 20 grams

Garlic ‒ 20 grams

Ginger ‒ 20 grams

Oil ‒ 100 ml

Soap water

Recipe

First, make a paste of the green chilies, garlic, and ginger, and set it aside. Wear gloves since you’re dealing with spicy ingredients. 

Next, combine the oil with this paste and set it aside for about 15 days. The idea is to let the oil absorb the pungent qualities of the ingredients. Basically, we will be using the oil to ward off pests.

After a fortnight, strain the oil and remove the residue of the paste using a strainer or cheesecloth. You have a spicy, highly concentrated oil, so your 3G solution is ready.

How to use it?

Now that you have the oil ready, you can use it. However, you will need to mix the oil with soap water before spraying it on the plants to prevent the leaves from becoming oily. Any oil that remains on the leaves will prevent transpiration and kill the plants, so make sure you mix the oil with some soap.

To do this, mix 5 ml of the solution to 1 liter of water mixed with some insecticidal soap and spray on the plants. It's a good idea to try it only on a few leaves to check how the plants react. Then, you can increase or decrease the amount based on how your plants react.

If you reside in cold regions, you can use slightly higher amounts, but you'll have to use just a little for best results if you come from warm areas. 

• Apichi

Using pesticides with oils like neem or other horticultural oils can irritate some people because the oils can suddenly kill your plants if you've never used them before. However, since the 3G spray contains oil, you may look for other alternatives. 

It is not possible to use the mixture directly on the plants without a carrier like oil. Therefore, you can replace the oil with another carrier such as alcohol to derive the same benefits.

Here's another recipe that uses alcohol instead of oil. Known as Apichi, it's an effective pesticide used against many pests, including red spider mites and aphids.

Ingredients

Garlic ‒ 20 grams

Hot pepper ‒ 20 grams

Black pepper ‒ 20 grams

Isopropyl alcohol or Everclear ‒ 30 ml

Recipe

First, mix all the ingredients and the alcohol and set it aside for 24 hours. Some people like to boil the mixture — garlic, hot pepper, and black pepper — and then mix it with the alcohol. Remember — alcohol is flammable, so never try to boil or heat it under any circumstances. It shouldn’t be anywhere near a flame. 

So, once you have a hot mixture of garlic and peppers, wait for some time until the mixture cools down a bit, and then mix it with the alcohol, so it doesn’t evaporate. You can also make a dry mixture of garlic and peppers and combine it with alcohol. Both methods work great.

Let the mixture sit for 24 hours. The alcohol will suck in all the spicy stuff. Next, add about one liter of clean water to the spicy mix and combine well.

Again, cover the mixture with a clean cloth and let it sit for 15 days. Finally, strain the mixture using the cheesecloth or strainer. Now you have a highly concentrated alcohol solution.

How to use it?

Like the 3G spray, the Apichi is too strong to be used on the plants directly. Therefore mix 10 ml of the solution with 1 liter of clean water and spray on the plants. Remember to use it on a small patch to test before going crazy with it. You can also use 15 ml with 1 liter of water if you still see some pests lingering around.

If you don’t want to take the DIY approach, here are other ways to get rid of pests in the grow room:

• Neem Oil

Neem oil is one of the most common organic pesticides used worldwide because it is safe, organic, and super effective at killing bugs, mold, and fungus. The best part is that this organic pesticide for cannabis is harmless to not only your plants but also you and your furry friends. Plus, it won't hurt friendly predators like ladybugs or pollinators like honeybees.

On the flipside, neem oil can spell death for invasive pests like aphids, mites, barnacles, inchworms, caterpillars, crickets, fungus, gnats, mold, grasshoppers, leaf miners, scales, spider mites, whiteflies, thrips, and many more. 

To use neem oil to kill pests on your cannabis plants, mix the oil with water as directed on the packaging; mixing with water is essential to avoid the strong smell of neem in your grow room.

Next, use a one-hand pressure sprayer or mister to spray the mixture evenly all over your plant right before the lights shut down or at dusk. Avoid spraying it when there’s too much light as it can burn the leaves. If you have to use it when the lights are on, use fans to dry the leaves quickly. 

It’s a good idea to mix the oil with soap water even if the manufacturer doesn’t recommend it because you don’t want the oil to settle down on the leaves.

We also suggest not to use neem oil if you're growing your cannabis for someone else, especially a medical patient, because some people may be allergic to neem, and some of its residue can end up in the buds.

• Azamax

Azamax is one of the most effective pesticides from General Hydroponics. The main ingredient in Azamax is Azadirachtin, that's also present in neem seeds.

Although neem oil is pretty efficient, many users complain that it does more harm than good. One of the main reasons is that neem oil will not work if you don't know how to use it. For instance, inappropriate water and oil ratios can stunt or kill the plants if there's a lot of oil residue on the leaves.

Azamax is an excellent alternative to neem oil. It's a broad-spectrum insecticide that works by starving and eventually killing the pests. In addition, Azamax is better than most synthetic insecticides you find today. 

If your plants suffer from spider mite infestations during the flowering phase, getting rid of them can be pretty tricky. Also, using synthetic pesticides during the later flowering stages can be detrimental as you smoke the buds later. However, Azamax can be used even during the last few weeks of flowering safely.

You can also use Azamax as a preventive measure before the pests appear. Or, you can use it as soon as you see some symptoms such as yellowing leaves, holes, and bite marks on leaves. To use, mix about 1-2 oz of Azamax per gallon of clean water and spray on the leaves until you're sure the pests are gone.

Some pests like grubs and even mites rest in the soil, so treating the soil can kill the pests before they increase in number. In such cases, a soil drench will work better than foliar applications. For a soil drench, mix about 0.5-1 oz of Azamax with one gallon of water and use it every fortnight.

• Spinosad

Spinosad is another organic pesticide for cannabis plants that's harmless to plants, children, and pets. Essentially, Spinosad is made by fermenting bacteria that affect the pests’ nervous system. 

Using Spinosad is relatively easy, too. Simply mix it with water and use a pressure sprayer to spray the areas where you see bugs, especially under the leaves. Also, you can be quite liberal as the spray is relatively dilute. 

However, note that Spinosad is effective for only a day once mixed with water, so mix small amounts and use it immediately. It is effective against crickets, grasshoppers, caterpillars, thrips, aphids, spider mites, and whiteflies. 

• Horticultural Oils

Evolution is the backbone of biology and, thanks to it, many plants have evolved to keep the bugs off naturally. These plants contain compounds, oils, and minerals that repel or kill pests, acting as natural pesticides.

Horticultural oils are just that — concentrated extracts of these bug-repellent compounds and oils that help you kill pests on your cannabis plant.

For this, you need to find a suitable horticultural oil and simply use a mister to spray your plant with it. It only lasts for eight hours, but if you spray it consistently, it is enough to rid your plants of nasty pests like aphids, barnacles, mites, spider mites, whiteflies, and a lot more. 

The best part is, unlike other highly effective pesticides, horticultural oils do not leave a film on your plant, so your plant won't be affected at all.

• Alcohol and Water

If you don't want to do a lot of research or spend a lot of money, we recommend using alcohol and water. It is effective against mealybugs, spider mites, and other common pests.

Mix rubbing alcohol and water in a 9:1 ratio. Next, spray the mix once a week on your plant until the bugs are all gone. It’s strong enough to kill the insects and pests. 

Another benefit of this pesticide is that alcohol evaporates within minutes, so it doesn't leave a film on your plant, either. 

The only downside with alcohol and water is that it does not cure an infestation, only kills the pests. 

• Diatomaceous Earth

Diatomaceous earth is nothing but fossil dust — sprinkle this powder on your soil and around your grow room to kill the pests.

This powder is harmless to the plant and us, but it is incredibly sharp at the microscopic level. It tears the bugs on contact and dehydrates them, eventually killing them.

Again, like alcohol and water, this cannabis pesticide is only suitable for bringing the number down, not completely getting rid of the insects. We recommend using this with other organic pesticides for cannabis.

• Caterpillar BT Spray

Caterpillar BT spray is a biological insecticide containing Bacillus Thuringiensis (BT) bacteria that effectively kills caterpillar larva and prevents grown caterpillars from eating leaves. 

There are various types of BT sprays, so choose the one explicitly formulated for caterpillars; it is suitable for leaf miners, moths, and inchworms, too.

Start applying the spray as soon as you see any signs of pests on the leaves, like leaf damage or poop. And keep repeating every week until the caterpillars are all gone. Since it is harmless to the plant, you can use the spray up to the day of harvest.

• Bugs as Pesticides

Poison kills poison, and the same principle works for bugs, too. So, the most organic, safest way to kill pests on your cannabis plant is using other insects!

In other words, you need to bring various friendly pests into your grow room as they can prey on other harmful pests. While you can add various insects to your culture, we recommend starting with these two.

• Ladybugs

As cute as they are, Ladybugs are ferocious predators of various pests, like spider mites, aphids, whiteflies, mealybugs, and other soft-bodied insects.

How ferocious? According to the Planet Natural Research Center, a ladybug can eat up to 50 aphids a day! So just adding a few ladybugs to your plants is enough to rid your culture of annoying pests.

We recommend only taking help from Native American ladybugs, not the Asian lady beetles, as they are pretty invasive. And release them in the evening on wet plants. 

• Lacewings

Another beneficial bug is lacewings, which feed on leafhoppers, aphids, spider mites, thrips, and mealybugs. They offer the same benefits as ladybugs, but they don't fly off once you bring them to your grow room. 

The only thing is they are sold as eggs since the grown bugs are pretty fragile, but if you follow the hatching process right, you won't have to worry much about lacewings for months to come. These bugs keep reproducing at a good pace without overwhelming you.

Prevention is Better Than Murder

The best pesticide for your cannabis plants is prevention. Bugs are annoying to have, and if you miss the right time, it may be too late to kill the bugs. So, whether you are just reading this article or looking for ways to kill the bugs on your plant, we encourage you to prevent the bugs in the first place henceforth.

Here are a few ways to prevent bugs from getting into your grow room:

• Check the leaves regularly

Check the leaves frequently for any signs of stress or bug bites. Look under the leaves in particular, as that's where most bugs hide during the day. 

Ensure no leaves have holes in them or are discolored. If they do, it may be a sign of pest infestation.

• Don't enter the grow room directly

Various bugs in your garden may hitch a ride on you to your grow room. So, we recommend not entering your grow room directly from outside. 

Instead, you can change your clothes before heading to your grow room to ensure no bugs get in the room with you. 

• Treat new clones

It doesn't matter whether the grower is your cousin or best friend — always use wide-spectrum organic pesticides on clones when you bring them to your grow room.

This is essential because even a few eggs are enough to start infestation and wreak havoc on your cannabis culture.

• Keep a fan running over the plants

Air circulation is an effective way to keep pests away from your plant — it prevents the bugs from settling on your plant and calling it home. This is because many bugs require the plants to be still to lay eggs or mate, and some just don't like the wind.

However, avoid using a fan if only one plant in your culture is infected, as it can spread the eggs around, making the problem worse.

Ensure Proper Usage of Cannabis Pesticides

We urge you to be extra careful whenever you use organic pesticides for cannabis plants. Organic pesticides are safe, but if you overdo them, you may end up harming your plant. Here are a few tips for you to properly use organic pesticides:

• Always identify the pest species first — you won't be able to solve the problem if you don't know what's causing it.
• Do diligent research and get a second opinion before using any kind of organic pesticides. We recommend talking to our growers here on Growdiaries. 
• Use the right pesticide for the bugs and use them as directed. The instructions are written by experts, and straying from that may cause unpredictable effects on the plant’s growth.
• Don't mix organic pesticides unless recommended by the manufacturer or multiple growers. Mixing pesticides will kill the pests, but it may overwhelm your plant and hinder its growth.
• Always do a patch test on new organic pesticides — you never know how the pesticide can affect the plant.
• Always look at the side effects the pesticide may have on the user to ensure your buds are safe to consume for everyone.

Summary: Best Organic Pesticides to Use for Cannabis Plants

Cannabis is our best friend, but bugs are their worst enemies. Thus, the enemy of a friend is our enemy, right? 

So, always be meticulous about who you let near your cannabis plants. Use only organic pesticides and prevent bug infestations as much as possible.

Use the pesticides and follow the tips and advice listed above, and you will be able to get rid of pests in your grow room quickly. However, don't be hasty and overwhelm your plants.