Private businesses, OTOH, I'm not too sure about. I was an assistant golf pro years ago. Just off the first tee we had a sign that read, "No women or beginning golfers before 2pm Mon-Fri and never on the week-ends." That could be perceived as discriminatory. But, it was a private club so no litigation ever arose. And certainly no public golf course could have ever gotten away with that. We're talking about flowers and cakes ferchrissakes. If that's a "civil rights" issue then I cannot imagine what would not be a "civil rights" issue.
Edit: tpyos.