Question
It has been suggested to me that I spray diluted kaolin clay on fruit trees for pest problems. Must this specific type of clay be used for this purpose, or can any type of clay be used? Thank you.
DAWN

Answer
Good morning Dawn,

There is a commercially available product (Serenade) that is prepared from kaolin clay.  The product is 95% kaolin clay.  The company also adds in soap and perhaps some other ingredients that help for insect control and helping the product not wash off in the rain.  They have done repeated testing to determine what rate to use on fruit trees to confirm that it is safe.  I would recommend that if you want to treat your trees, to use the commercial product.

If you are trying to make your own, you should only use kaolin clay.  This is the only clay product that has been tested safe and effective.  Other types of clay may vary slightly in particle size and mineral content which will change their effectiveness.

Should you prepare your own product, I would begin by spraying a small number of trees.  This way, you can verify that the leaves are not delayed or damaged by your treatment.  I have heard horror stories of how growers have tried to make their own product and killed or damaged their trees.  If your product appears to be safe, you can treat additional trees. I encourage you to use caution and monitor your test trees for several days before treating the entire crop.

Good luck with your trees,
Jen