Can Bayer Advanced 3-in-1 Insect, Disease and Mite Control concentrate* used as a diluted soil drench? I contacted Bayer but the representative simply read off the label and said it's meant to be used as a spray and can't guarantee its effectiveness as a soil drench. Has anyone used this popular product as a soil drench? Is there something about the formulation that only allows it to be effective as a foliage spray? I would like to use this both as a foilage spray and a soil drench so that I can kill pests on contact and also have the plant internalize the insecticide/miticide.

Some background: my brugmansia is being attacked by all kinds of pests from red spider mites, whitefly, caterpillars, earwigs, and other leaf-eating insects. I've tried insecticidal soap with very limited success (this might have to do with the fact that I can't keep up with the spraying schedule). While the damage is mostly cosmetic for now, the damage is getting worse each week. It's becoming too painful to look at every time I pass by them in my garden. I would like to stem the infestation to a point where beneficial insects can keep these pests under control.

*label:https://www.bayeradvanced.com/~/media/BayerAdvanced/Product%20Labels/3%20In%201%20Insect%20Disease%20Mite%20Control%20-%20Concentrate%20-%20Roses%20Flowers%20Shrubs%20-%2032%20oz.ashx

Thank you

I've used it on the soil, but I wouldnt say "as a drench." When the spray didn't do the trick, I resorted to watering the pot with the solution. I figured it would kill anything in the pot too. The last couple of years, I have covered the top of the pot's soil with coffee grounds. I'm not swearing that it has been effective, but I only found one brug with spider mites. We've had a lot of rain this spring. The mites just may be waiting for me to turn my back!

And welcome to NGA!

I have no problems so far with mites on my brugs. And believe me, we have a lot of everything here in FL. When I used the Bayer 3-in-1 on them, it only lasted a few months then the mites and other bugs developed immunity to whatever the insecticide in it is. That's the fatal flaw with systemic insecticides.

Soapy water also works but is not easy to cover with, and I also found it makes the plants photo-sensitive i.e. the leaves burn in the sun if the soapy water is on them when the sun hits. I had to spray with the soapy water in the evenings, then rinse the plant off with the hose the next morning, early.

Now, I just make a point at least once a week to spray/drench the whole plant with the hose, being sure to wet everywhere, including the undersides of the leaves. Mites hate wet weather, and they seem to be washed away by this treatment, so I'm just going with what's working now. Yup, plain water sprayed from the hose. Once or twice a week minimum unless it rains.