Where do you live? There are farmer's markets of some sort every day. The ones I frequent:
Sat morning at Kapiolani CC: crowded, touristy, huge. Lots of good produce, though.
Sat morning in Hawaii Kai: smaller & less touristy than KCC, run by the same folks as the Haleiwa one.
Sun morning in Haleiwa: good excuse to get to the North Shore. Lots of local (North Shore) farms.
Wed afternoon at Blaisdell: smaller than KCC but run by the same folks. More prepared foods and less veggies than I'd like. I don't go so often any more.
Thurs afternoon in Makiki: nice neighborhood market. Smaller, but on my way home.
T/Th/Sun at Manoa Marketplace: just a couple of stands, mostly (but not totally) resellers. Some of the stuff is local, some not. If it's not marked, just ask.
I'd like a CSA, too... used to have one in Rhode Island. There's a few similar things here, but not quite a CSA. One of the egg sellers has a punch card... pre-pay for six dozen eggs at a big discount, then get the card stamped when you pick them up.
I think Just Add Water does a CSA, but they're small and at their booth don't always have the stuff I want, so I haven't participated in it:
Just Add Water Community Supported Agriculture