All-Natural Pesticides – Safe Up to Harvest!

by Nebula Haze

Got bugs on your cannabis plants? A pest infestation can be a grower’s worst nightmare, but luckily there are ways to get rid of the bugs without harming your plants or affecting your buds. This list of all-natural remedies will get rid of a lot of different types of bugs without harmful chemicals!

These pest remedies can be used up until the day before harvest!

Aphids can be an annoying garden pest, but with these all-natural pesticides you don't have to worry about them!


I know, I know, this seems really basic, but the best way to prevent an infestation is to either prevent it altogether or catch it as soon as possible.

  • Check leaves at least weekly for signs of stress or bug bites. Check underneath the leaves and all over the plant. Make sure none of your buds are becoming discolored.
  • Don’t go straight from outdoors to your grow room. You may accidentally track in bugs from your garden. I’ve also heard of a case where someone bought a bouquet roses for their wife and the roses infected their garden with spider mites! Just be careful what goes in the grow room!
  • Even if you trust the grower, treat new clones with a wide-spectrum but natural pesticide like neem oil, just in case the clone is infected (this is the most common way growers get bugs in their grow!). Even 2 or 3 eggs on your clone is all it takes to start a new infestation! Some growers might not even realize they have bugs so it’s up to you to make sure they don’t get in the grow room!


Table of Contents

  1. Remove or Spray Off As Many Bugs As Possible
  2. Fan Blowing Over Soil & Plants
  3. Neem Oil
  4. Insecticidal Soaps
  5. Spinosad
  6. Essentria IC3
  7. Caterpillar “BT” Spray
  8. Alcohol & Water
  9. Diatomaceous Earth
  10. Floating Row Covers
  11. Traps
  12. Beneficial Insects


1.) Remove or Spray Off As Many Bugs As Possible

I know this might seem obvious to some people, but I didn’t really think about this until someone told me!

If your plant is heavily infested, it’s a good idea to try to cut down their numbers in every way possible even before you treat them with something. Depending on the infestation, one way to do that may be to simply move your plants outside and spray as many bugs off as you can with a power sprayer.

It’s also a good idea to remove leaves and buds that are heavily infected, especially if you see lots of eggs under the leaves. If you have some sort of fungus or mold, carefully remove the infected areas without touching any healthy plant tissue.

If possible, spray off as many bugs as you can, and remove heavily infected leaves

A One-Hand Pressure Sprayer is perfect for misting plants

2.) Fan blowing over the plants and top of growing medium 

Not only do plants grow better with a breeze, great air circulation is great for pest prevention. A breeze also helps pest treatments go better if you have an infestation already because fans help spray treatments dry on the plant.

Many types of bugs don’t like the breeze and can’t mate in windy conditions. Some bugs need wet topsoil to survive which can be prevented with a windy environment and good watering practices. When choosing an outdoor spot to grow, it’s a good idea to pick a breezy spot if possible.

If you’ve got one of the problems listed here, a strong breeze blowing over the plant will help a lot!

Effective against:

3.)  Neem Oil

Neem Oil is safe, organic and effective at many bugs as well as molds and fungus. Generally I’ve found that when you mix it with water as directed, it doesn’t have a crazy strong smell (reminds me of garlic and sort of earthy) and the smell doesn’t stick around for long. As far as safety, you can use this product up until the day before harvest. But, as with any pesticide, always try to avoid letting any get on your buds because it may end up affecting their final taste/smell if it doesn’t have enough time to dissipate first before harvest. If your plants are infested with bugs bad enough that the buds themselves need to be treated, it’s often time to harvest anyway!

That being said, Neem oil is an all-natural remedy that is very effective against many different types of bad bugs and mold, but won’t hurt humans, animals or most “good” bugs like bees, ladybugs, predatory wasps, etc. You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly since neem oil and water can separate easily.

Use right before the lights go out (or the sun goes down) so it doesn’t burn your leaves.

Get Neem Oil Extract on!  A One-Hand Pressure Sprayer is perfect for misting plants

Effective against:

4.) Insecticidal soaps

Fatty acid salts or insecticidal soaps weaken the outer shell of bugs but are safe for humans and don’t leave much of a residue.

With soaps, coverage is very important as it does not stay on your plant for long, so follow-up applications may be necessary. Although this is considered safe, avoid getting any on your buds so it doesn’t affect the taste/smell!

Get Inseticidal soap to kill cannabis aphids - available on!

Effective against:

5.) Spinosad

Spinosad Products are organic and completely harmless to pets, children, and plants. Spinosad products can be used directly to kill bugs on contact and should be sprayed liberally anywhere you see bugs and especially under the leaves. Although maybe not as strong against pests as some of the more harsh insecticides, it does work and it’s very safe for plants, animals, and humans!

Spinosad products are organic and kill spider mites, caterpillers and thripsA One-Hand Pressure Sprayer is perfect for misting plants

Effective against:

Spinosad is an organic insecticide made from the fermentation of a specific soil bacteria (actinomycete Saccharopolyspora spinosa) and kills bugs via ingestion or contact by effecting the insect’s nervous system. Spinosad can be a good choice for organic and outdoor growers, because it is very toxic to many pests, but is less toxic to many beneficial insects and spiders.

Note: Most spinosad products are effective for only about 24 hours after being mixed with water, so only mix as much as you will need per application. Anything left over will be waste.

You will need a mister (also called a “One-Hand Pressure Sprayer”) to cover all the leaves evenly when spraying them with spinosad products.

6.) Essentria IC3

Essentria IC3 Insecticide is a mix of various horticultural oils that is organic and safe for humans. It is often marketed as a “bed bug killer” but it can be effective against many bugs when the plants are treated regularly. Unfortunately it only stays effective on the plant for about 8 hours so you will want to either apply this daily or combine with other options. You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly.

Get Essentria IC3 insecticide on - this can be a tool in the fight against broad mites or A One-Hand Pressure Sprayer is perfect for misting plants

Effective against:

7.) Caterpillar “BT” Spray (safe biological insecticide) 

This biological insecticide contains the bacillus thuringiensis (BT) bacteria which kills larva and prevents caterpillars from being able to eat. Make sure to get something labeled for caterpillars, as there is a different type of BT that’s good for killing mosquitos, but isn’t as effective on caterpillars.

It doesn’t work every type of bug, but this is one of the most effective ways to kill caterpillars, and won’t hurt most beneficial insects. As a bonus, it can also kill some other cannabis pests like worms and moths.

If you see caterpillar damage, try a “BT” spray. It’s very safe and makes it so caterpillars can’t eat.

Example of leaf damage inflicted by a caterpillar / inch worm on a marijuana leaf

Apply a caterpillar BT spray as soon as you see leaf damage, caterpillars or caterpillar poop. BT sprays work best on small caterpillars that are actively eating your leaves. Repeat every week for as long as you’re still seeing caterpillars, though you can give BT more often if there’s a heavy infestation. Make sure to thoroughly mist both the tops and bottoms of leaves, and apply again after a heavy rain (since that will wash the BT away).

Recommeded: Monterey BT Spray
(though any caterpillar BT product will work!)
Get BT spray on Amazon!

Or save some money in the long run by getting the concentrated version with a mister

BT products work well on caterpillars, and are safe for most beneficial insects!A One-Hand Pressure Sprayer is perfect for misting plants

Since BT is harmless to humans, you can use BT products up to the day of harvest! One thing to keep in mind is BT spray almost instantly stops caterpillars from being able to eat, but doesn’t kill them directly. So although you may see the caterpillars alive and apparently unharmed after spraying, the BT is still doing its dirty work because they’re slowly starving to death.8.) Alcohol & Water

Make a solution of 9 parts water to 1 part rubbing alcohol and spray plant once a week until bugs are gone. With an alcohol-water mixture, the goal is to spray the bugs directly to kill them. Since all the alcohol will evaporate into the air within minutes, it won’t give your plant a protective “coating” like soaps or oils.

This will likely not cure an infestation, but it’s very effective at bringing numbers down quickly!

Get rubbing alcohol on Amazon.comA One-Hand Pressure Sprayer is perfect for misting plants

Most effective against:

9.) Diatomaceous Earth 

Diatomaceous Earth is basically fossil dust which you sprinkle on the top of your soil, and anywhere else in your room (window sills, doorways, etc). This powder-like substance is harmless to mammals and plants, but is incredibly sharp at the microscopic level. Therefore it will tear and dehydrate bugs on physical contact. This will not get rid of an infestation, but can help prevent, control and slow things down when used effectively!

Effective against:

  • Almost every type of bug is at least detered, and it’s particularly effective against smaller soft-bodies insects and larva

10.) Floating row covers

These may not be the best choice for all cannabis growers, but these are very cheap and effective against many types of hard-to-stop bug because it physically prevents them from getting to your plants, while still letting light in to your plants. You can also water your plants through the netting. These are sometimes used to make mini “green houses” on the plants, or some growers will just drape them over the plant as they’re so light and airy they don’t really bother the plant.

These are much easier to use and are more effective with smaller plants, as it becomes difficult to fully cover larger plants. However, for young plants these can be great! They also protect your plant from wind and some harsh conditions.

Floating row covers look like thin netting or mesh and provide a physical barrier against pests

11.) Traps – Physically Capture Bugs

There are certain types of traps that physically capture bugs instead of kill them.

  • Crickets – Cricket bait & Cricket traps
  • Fungus gnatsYellow sticky cards
  • Slugs & snails – Make beer trap: mix flour with some stale beer and use it to fill a shallow container. Place in garden with the rim 1 or 2 cm above the ground so that slugs and snails can climb in. Substitute beer for wine, sugar water, juice, or water mixed with yeast. BE WARNED, the trap will fill up quickly so come back often to empty.

12.) Beneficial Insects

Beneficial insects may eat large numbers of bugs and are welcome guests in the garden. Many of these can be ordered online so you can release thousands into your garden at once. These natural enemies may not be enough wipe out pests, but can definitely help cut down on an infestation!

Add These “Good” Insects for the Garden


Parasitic wasps

Predatory mites



List of Cannabis Pests, Bugs & Viruses



Noooo, spider mites!!!!

No spider mites!

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