Pyrethrins, pyrethrum, pyrethroids

Paul Stamets tells the story about a USDA agent inspecting his mushroom “caves” observing that there were lots of flies. Composted horse manure is a favored bedding material. He advised Paul that “XXX” is approved for mushrooms since it breaks down after three days. Paul replied that it does break down in sunlight. Word has it that the agent turned white. Don’t know whether he wrote that label.

There has been discussion of using pyrethrin to control spider mite, thrips, and white fly. Beware. Timing of application before harvest is an issue about which I could find nothing when it comes to edible (smokeable) blossoms. Many people aren’t aware that while pyrethrin, a natural compound obtained from chrysanthemums, among other plants, is approved for use in organic gardening, pyrethrum is not. Nor are any pyrethroids which are synthetic analogs of pryrethrin. I’d like to use pyrethrin in my greenhouse where both white fly and spider mite are sometime visitors, but I need some guidance as to safe application schedules. I suspect that the issue is not as clear cut as it sounds when it comes to vegetables. Vegetables and most leaves have a waxy surface that we wash before consuming them. Buds, not so much.

I think discussion of the breakdown of insecticides when they are used indoors under artificial light also is warranted. Some of the finely tuned light sources may or may not include ultraviolet in their spectra. Pyrethrin attached to carpet dust has been shown to persist for two months or more (presumably indoors under artificial light).

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Well when it comes to insecticides chemicals near or in flower are not always the way to go and should be avoided there are many less harsh options and we actually have a thread on this topic @garrigan62 if I could remember the name of the thread lmao.


Yup give me a min…thinking

was a discussion on preventative care in grow room lol can’t remember the tread name either

Is this it Donald ?


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I believe so :slight_smile:

Thanks Will read almost every post under the sun after awhile can’t remember the titles of any lmao

Hi ryarnell. I am concerned about a build up of any toxins and spider mites can develop a resistance.
I wash prior to entering the garden room especially my hands, wear clean clothes that have not been outside. I have found that some people are just bug magnets so I really only show my garden through picts. absolutely do not let the ladies go dry this seems to bring em in for sure. As for a foliar spray I use a bee keeping solution that includes spearmint, lemongrass and sucrose. Just a cap full per quart of water. The product is called honey bee healthy. I think mites work through scent I don’t know about thrips and white fly. I got some clones one time that had thrips. I freaked out and killed all my plants intentionally. I spray during the dark period every three days or so when I know mites are present and the stuff puts em in their place. I have also found that inspections during the dark period are more productive using a green light headlamp.

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I picked out several quotes and under them I posted a link
Check out there products they use the same stuff and its all organic right up to harvest.


To control spider mite, thrips, and white fly. Beware. Timming of application before harvest is an.
( issue ) about which I could find nothing when it comes to edible (smokeable) blossoms.

Then and I quote ; Vegetables and most leaves have a waxy surface that we wash before consuming them. (Buds, not so much.)

He’s talking about washing the vegetables but ( "key Words Here ( BUDS NOT SO MUCH )

Interesting information. Now; If we can only find that article. Thanks for sharing RY. :smiley: Many articles here need some updating, as Robert has been writing them for years, and sometimes thing get confused in the translations.

Thank You for bringing this to our attention. Hopefully soon I will be able to go through the archives. It will be a marathon; So, please be patient.

Latewood :slight_smile: