Question about spinosad and soil drench

Hi nerds,

ive finally found somewhere to get some spinsad at a fairly reasonable price over the pond here in the UK.

For peeps that wanna know I ordered from the US amazon site, £26/$40 delivered for a 32oz bottle of the Monterey brand.

ok, so how do I go about doing the soil drench, shall I do it just before I use the soil, like a few days before, or do it after I've mixed everything and before letting it cook?

If u could give me what ratios you use and when I'd appreciate it, I know subs not about here now and don't wanna send him a email just asking this, lol. But I'd like to follow subs regime as its obviously working. I Know he does soil drench and also sprays in veg so just would like to now how much and when.

I'm thinking off jus doing the soil drench as that's where the bastard thrips are coming from.

thx nerds.

A soil drench and a good leaf spraying is all that's necessary......since I don't know the brand it's difficult to tell you the proper ratio's. Multiple applications may be necessary since it generally controls insects, but may not wipe them out entirely each application. Every manufacturer uses it in different proportions. Read the enclosed directions on the container and follow them closely.

It's the Monterey Garden Insect Spray one, cheers for the info, haven't received it yet but wasn't sure if it would mention amounts for soil drench as the label seems to imply its for spraying, from what I can read of the pic anyways,lol.

also does spinosad kill any of the bene bacteria and fungi? Or does it just focus on soft shelled insects and larvae. I'm presuming not as people wouldn't use it otherwise.

What are you using spinosad for?? In horticulture, it is called Conserve and make by Dow Agrosciences. We use it in the greenhouse where I work for thrips. That's it's main use. It can be used for spider mite control at higher rates. It is not systemic, so doing a soil drench will not help the foliage unless you wet the foliage during the drench. It can also be used for lepidopterous which are worms and caterpillars and for fireants.
Conserve is 11.6% spinosad. Monterey's spinosad is 0.5% active ingredient. I worked for Dow in Indianapolis, IN during the time it was developed. It is made by a fermentation process. It will not kill anything fungal related. The rate you use depends on what you are spraying for. If you are using beneficial predators such as cumumeris for thrips, it will kill them. It works by contact. Thrips can become resistant to it, if used too often.
For the best info, visit www.cdms.net, under services, click Labels/msds and type it Conserve in the search window.

its basically to control thrips which seem to be in most soil these days, I don't want to be spraying my plants much and my thinking is that they are coming from the soil, the drench should kill all larvae so I won't have to spray plants.

id just like to know what amount per litre to add to use for soil drench as I'm presuming the label won't say.

its a pretty common brand and I think it's the same as sub uses, again, I'd just like to know when the best time to do a soil drench on my super soil that's being cooked and base soil. I'm presuming the best time would be a few days before I use it.

no wonder sub left this site, I'm asking a basic question and people are quite happy to post comments but don't actually answer anything I wan to know.

i know all about how spinosad works, where it comes from and the dangers of using it, I just need to know how much per litre to use and best time to use it.


So again folks, if you use the MOnterey brand of spinosad and do soil drenches on your soil, how much do u use per litre and what's best way to apply, do I just pour a few gallons in my bins of soil, enough to soak all the soil and just leave it soaking a bit or shall I put the soil in something that drains and just water through a few times like a soil leach. I'm presuming as it kills on contact just flushing through soil once or twice should be ok.

so again to simplify for folks here's the 3 questions I would like some advise on.

1: how much Monterey branded spinosad shall I use for a soil drench to kill thrips larvae in soil in ml's per litre/gallon of water.

2: when and how is the best method of applying the drench, with or without drainage etc.

3: does Spinosad kill any beneficial fungi or bacteria, trichoderma etc (I don't use nematodes or bene insects and is indoors so only worried about the soil web)

thanku in advance, I should have used subs motto and just googled it, lol, but I thought it'd be quicker asking folks, how wrong was I.

3 questions I would like some advise on.

1: how much Monterey branded spinosad shall I use for a soil drench to kill thrips larvae in soil in ml's per litre/gallon of water.

2: when and how is the best method of applying the drench, with or without drainage etc.

3: does Spinosad kill any beneficial fungi or bacteria, trichoderma etc (I don't use nematodes or bene insects and is indoors so only worried about the soil web)

thanku in advance, I should have used subs motto and just googled it, lol, but I thought it'd be quicker asking folks, how wrong was I. [/QUOTE]

Question 1: I think the rate for fire ants would be a safe rate. It's 2 oz/gallon = 60ml/gallon = 0.6ml/gallon. We have only use Azaderactin products at work for thrips larvae in the soil. The rate for Conserve for fire ants is 8 oz/100 gallons = 2.4 ml/gallon. Conserve has 23.2x the a.i. that the Monterey product has. 2.4ml x 23.2 = 55.68 ml/gallon. Fire ants are not thrips of course, but the spinosad will have the same mode of action wheather killing fire ants or thrips. I know this is not the answer you are looking for, but since anyone else has yet to comment, you should feel comforatable using the 2 oz/gallon of the Monterey product without concern for any adverse affects.
If you have access to bios, orius (minute prirate bug) works great at eating thrips.
You can put bush beams or eggplant with your plants to use as trap plants and maybe pull the thrips from your plants. We have been using those as trap plants at work for years. Trap plants are recomended Brian Spencer at Applied Bionomics out of B.C. He has been in the beneficial insect business for decades. When your room is empty, putting in bush beans or an eggplant will attract any critter that is in the room to it, so it's good to find if your room is clean from insects before you moving your plants in.

Question 2: The thrips larvae should be in the 1st few inches of soil. As long as you drench down a few inches, you should get them. I would do 1 application/week for 3 weeks. A sprinkling can works fine for drenching, done it many times. Just check that you water enough to wet the media a few inches down, maybe just 2-3".

Question 3: The spinosad should be harmless to soil life. I did not find spinosad listed on the compatability chart on Bioworks web site. You probably already know that they sell Rootshield, the number 1 product with trichoderma. Probably because spinosad is not used in greenhouse setting as a drench. There are some wicked pesticides that are safe with trichoderma, so I'm sure spinosad would be. It's unlikely that it would harm any bacteria.

Sorry that I can not say I used it and it's safe and works great. Hopefully some one who has actually used spinosad drenched will reply to your post. Good luck with getting the answer you need to go ahead with your work.

Hey Bob, check out the Weed Nerd episode 23, (about 8:00). Subcool explains how he applies Spinosad. He's using 2 tablespoons per gallon of water when used as a spray, and 4 tablespoons when used as a soil drench to control thrips, gnats, and mites.

Also, check out Weed Nerd episode 36 (16:30) he applies Spinosad to his SS mix just after stirring (and before cooking) as a spray. Hope this helps!

Certainly not healthy for your Bene's Bob. I wouldn't use Spinosad as a preventative measure... think about it. Since it kills thrips and other insects... it's gonna kill your benes!

My advice would be to use beneficial predators if your REALLY THAT CONCERNED that your bagged soil is contaminated with shit already... For instance, I pre-innoculate my medium with Met-52 (made from a naturally occurring soil fungus) for root aphids and their larvae and pre-innoculate with BTI (made from a naturally occurring bacterium) for fungus gnats and their larvae. I haven't personally use beneficial predators for thrips, but consider beneficial predators like Green Lacewings or predatory mites.

Just google thrips, biological controls, predators, etc.

Is it really worth killing/hurting your beneficial bacteria, fungi, nematodes, etc.??

I understand your concern Bob, but have you ever had thrips come in your medium before???

Ive been spraying the shit out of my SS with 1 gal/4 tbsp. monterey mix. Left my cans on side of house and it seems like some little flying bugs infested it after i tore up a bunch of weeds and shit out front.. There was quite a lot of bugs in the soil on monday, I dumped out the soil and flipped and mixed it as I already needed to do so. Sprayed while it was out, flipped and sprayed again. Put it back in can and sprayed the top layer pretty heavily, sprayed again on thurs and today.. Fast forward to saturday (today), I will only see 1 or 2 of the bugs now if im examining the soil for a few minutes, i feel like there is more of them in there if not eggs etc.. Pretty nervous that there is any bugs at all, should have kept in garage!


On the bright side, the monterey seems to be working pretty good.. But i was really hoping that with the amount i sprayed there wouldnt be a single thing moving in there. Oh well hope for the best, if not its lookin like im spending a pretty penny on some bagged TGA SS. Only about a month before I need it, lets hope i can get it under control.

Im sure it has some effect on the living benes in soil, but it makes me feel a little better to see and hear subcool uses it as a drench... Gives me a little hope haha.

How's it going guys. I found this thread and wanted to add .02 cents.
Firstly, it will take a few applications to kill everything in the soil..I had a super soil bin get aphids and it took a good 3 times to kill anything that moved. I do think that I over applied as the soil later seemed tainted and caused issues with some testers. I tried just a root drench on a hydro plant, and.it burned that too. Just just start small on dosage as too much can hurt the root zone in my experiences.
Also..met-52 is a monsanto product for a while now..not sure if that changes its benefits for you but there is some debate amongst probiotic farmers. Here is a link: http://www.forbes.com/sites/davidkroll/2013/12/13/the-bioag-alliance-monsanto-and-novozymes-team-up-on-agricultural-biologicals/

duster74 said:

Hey Bob, check out the Weed Nerd episode 23, (about 8:00). Subcool explains how he applies Spinosad. He's using 2 tablespoons per gallon of water when used as a spray, and 4 tablespoons when used as a soil drench to control thrips, gnats, and mites.

Also, check out Weed Nerd episode 36 (16:30) he applies Spinosad to his SS mix just after stirring (and before cooking) as a spray. Hope this helps!

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Wow, 4 tablespoons a gallon for soil drench, some good info, did a teaspoon to a gallon this morning for a soil drench, the next one will be 4 tablespoons...thanks! And episodes 23-24 are not up..what da!? https://www.youtube.com/@subcool420/videos

Week4@inCharge said:

Wow, 4 tablespoons a gallon for soil drench, some good info, did a teaspoon to a gallon this morning for a soil drench, the next one will be 4 tablespoons...thanks! And episodes 23-24 are not up..what da!? https://www.youtube.com/@subcool420/videos

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I use 1 - 2 oz/gallon for a soil drench depending on how badly I'm battling thrips. They are endemic around here.

curious2garden said:

I use 1 - 2 oz/gallon for a soil drench depending on how badly I'm battling thrips. They are endemic around here.

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Thanks, I'll have to add some more then, my usual routine of beneficial insects is struggling this grow. I've had lots of luck but not this round, I hate to use it but if I have to I'll break out the Spinosad. It's every creature for themselves right now. 4 tablespoons (1-2 ounces) it is!