How can I keep green caterpillars from eating my flowers?

Apply food grade diatomaceous earth.

Crushed egg shells keep the critters away. I put them around my plants.

You need to identify the type of catepillar, can you take one to your garden center? Lady bugs early on may prevent the catepillars from ever developing. Diatomaceous earth is also great for slugs.

I try not to use harmful chemicals in my garden because of the bees so I purchase live ladybugs from a company called HighSierra ladybugs out of California. They will send them to your home via UPS. The instructions on how to release them into your garden will be with the ladybugs. The ladybugs will take care of the bug problem. If you want the ladybugs to remain in your garden they will need a ladybug habitat for the winter months.

my mom was the gardener but she mix up dish soap and water and spray the plants she never had any bugs and she grew all kinds of things hope this helps

Thank you so much!!! I like that answer the best so far.