What’s the deal with Spinosad? Is it safe for growing weed?

Published Jan 29, 2021

by Nebula Haze

Spinosad is a common natural insecticide that’s used to kill a wide range of cannabis pests from aphids to caterpillars to spider mites. It’s considered a broad-spectrum insecticide that is both organic and effective.

A common Spinosad product in the US is Monterey Garden Insect Spray

Spinosad products are organic and kill spider mites, caterpillers and thrips

Note: Trade names include Monterey Garden Insect Spray, Bonide, Captain Jack’s Dead Bug Brew, Conserve SC, Entrust SC, Elector Baid, Natular, Regard, etc.

But is it safe? Can it cause harm to humans if it’s used while growing cannabis plants?

Important facts about Spinosad

  • Organic and generally considered safe and effective
  • Low-toxicity to humans, pets, and plants in normal applications
  • BUT not allowed for use by commercial growers in several parts of the US and Canada

What’s the deal? Is it safe or not? Why is it banned in some places but not others? Today you’ll discover the answers to all those questions and more.

Spinosad – not for commercial growers!

Cannabis plants love bright, direct sunlight

What is Spinosad?

Spinosad is an organic insecticide created via fermentation by the soil bacteria Saccharopolyspora spinosa. The smell reminds me of wet dirt. It is a mix of two specific compounds: spinosyn A and spinosyn D. Spinosad kills bugs via ingestion or contact by attacking the insect’s nervous system. It can be a good choice for many organic and outdoor growers, because it is toxic to many common cannabis pests, but is less toxic to most beneficial insects and spiders. Targeted insects typically die within 2 days of contact or ingestion.

It’s used as a foliar spray on your plants. The plants are misted with water that contains Spinosad, which stays effective for about 24 hours. However, residue can still be found on plants for weeks or months after it stops working, especially in an indoor growing environment where plants are never washed off or rained on.

Spinosad is also commonly used as flea protection on dogs and cats, since it kills fleas but isn’t harmful to humans or if pets eat it. Some people use it to kill lice as it’s less toxic than the more common permethrin.

What is it effective against?

Spinosad can help fight infestations from the following common marijuana pests:

Click on each link to get a full explanation of the pest along with recommended treatments for infected cannabis plants.

Why is it banned in some places? Is it dangerous?

Spinosad has been banned for sales or commercial use in the following places. As far as we know, there is no comprehensive list of places where it’s regulated in this way, so we’ve pieced this list together from talking with growers around the world.

  • USA (available but banned for cannabis growers in the following states)
    • Michigan
    • Montana
    • Oklahoma
    • Oregon
    • Washington
  • Canada (not available for purchase, currently under re-evaluation by the Canadian government)
  • Denmark
  • …and possibly more! If you’re worried, use an alternative product.

Please contact us if you know of more places. We’d like to eventually have a complete list.

Why? Spinosad is toxic to honey bees as well as some common pest predators. Since it indiscriminately attacks caterpillars, it also can hurt the local butterfly population. Another commonly cited issue is that, although it’s generally accepted that Spinosad is safe for edible crops (since people can safely eat it) there have not been studies on how it affects humans during the smoking process.

However, if you’re growing commercially it’s highly recommended to avoid Spinosad altogether no matter where you live. Although it’s organic and effective against a wide variety of bugs, the fact that some places regulate it should be enough to stop you. On top of that, there are other (typically more effective) treatments for each individual bug that Spinosad fights.

And if you are looking for a “kills all bugs” panacea, you will get similar or better results with ones that combine insecticidal soaps, horticultural oils, alcohol, and other natural insect killers that won’t leave a residue on your plants that is illegal in some places.

We’ve removed Spinosad off GrowWeedEasy.com

Although we feel confident that Spinosad is safe to use on cannabis plants, we don’t want to lead growers astray and have their weed rejected by regulatory agencies. Therefore we’ve done an audit of our site and either removed Spinosad where it’s listed or included a warning for commercial growers.

What has been your experience with Spinosad? Let us know!

Chemical structure of Spinosyn A and D


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