Bought generically from suppliers of pottery clay or as an EPA-registered product called Surround WP, this material is mixed with liquid soap and water. When sprayed on plants, it forms a mineral film that grasshoppers don't like. It works well to repel them.

Here's my recipe: Mix 1 quart of kaolin clay and 1 tablespoon of liquid soap with 2 gallons of water, or follow label directions. Spray the plants thoroughly.




Question: I have a grapevine in my back yard. Every year, it is loaded with grapes, but they disappear before I can get any. I guess birds must be eating them. Is there a way to protect them? There appear to be many young grapes this year.  G.O., Fort Worth

Answer: In this case, I would use kaolin clay.   Mix 1 quart of kaolin clay and 1 tablespoon of liquid soap with 2 gallons of water and spray the plants thoroughly.  The white mineral film left on the leaves and fruit repels hard-to-control insect pests such as grasshoppers and should help repel birds. A commercial equivalent to my mixture is a product called Surround WP. I hope you won't have to resort to covering the plants with bird netting.

 
Apple tree treated with Kaolin Clay.
Photo from ARS