Sounds like flea beetles. I have read that neem and insecticidal soap help. I used rotenone on my eggplants one year when completely overtaken by the creatures, rotenone is a botanical pest control but should still be used sparingly and only when necessary. Also, have read about using garlic, onion, and mint sprays. Not sure what the ratio of water to garlic, onion, or mint would be, but I bet you could look up a recipe for it very easilyI really like this idea and if I am bothered this year, plan on giving it a tryAnd, of course, when dealing with something like a delicate green, you should look up if it can handle certain methods.
I could be wrong but it does sound like flea beetlesHope this helps!
I could be wrong but it does sound like flea beetles