Mik, DY is right. I get what you’re saying, but with the way you worded it, it’s a big risk of lifnei iver if taken at face value. One can NOT buy a bag of lettuce without a hechsher. The OP was inquiring about pre-packaged things; you’re talking about fresh, loose produce in grocery stores.
Also, I don’t think I’ve ever seen fresh dates sold out in the open in a grocery store. Commercially, they’re almost always dried or frozen or some such thing, and would require a hechsher.