I make our own business cards using a photo of one of our sunflowers. I use Avery's business card template. It takes a bit of tweaking, but it really isn't that hard. If you know someone with a bit of MS word savvy, they might well be able to do one for you. You could offer some of your produce in exchange.
Our card is quite simple. The sunflower pic, our name, based on SO's family name (recognized in our area) and the usual address, phone and email.
I can always write additional info on the back.