When using DE to fend off pests, what is the best solution to use it?

When using DE to fend off pests, what is the best solution to use it? Obviously it is in a spray bottle with PHed water, but how much? Can you hurt your plants with an incorrect DE solution?

I have only used it outside as a powder spray on my sunflowers and tomatoes.or to pour on the wood pile to stay off the earwigs. I have not treated any MJ with it. I have heard it clumps if you dress the topsoil.


DE is nothing but tiny microscopic skeletons made of glass. The glass is so sharp it cuts the outer skin of bugs and they dehydrate from the cuts. It has zero effect on the soil. Its best used dry and you can sprinkle it on the top of the soil with an old salt shaker or a small can with a nylon type stocking cover. Reapply as often as you want. In between watering’s works well.
SEM pic of diatoms


I use DE as a top dress after every watering after the top dries out just a bit. Ne effects on plants or tds numbers. Just a great bug killer. Can be used as a foliar spray as well.


It does, I have tried that and was told it would create mold in the soil and to not do that. That is why I was thinking a foliar spray.


I add about 2 inches of inert washed sand as to top layer to my pots. This separates organic material from the bugs and and fungus that need organics.
Some beneficial microbes are an excellent way to keep your root zone colonized with the good bugs that prevent the bad bugs from invading while also breaking down salts in your soil providing the mechanism to uptake into your root system.