Sorry for the brevity of my last post. I posted from my phone.
The two producers at the Green City Market that I have in mind are
Tiny Greens and
Three Sisters Garden. Tiny Greens specializes in this and they have a larger selection. Three Sisters is fast becoming one of my favorite stops at the market. In addition to micro sprouts and greens, they have incredibly good rolled out, black beans, cornmeal, and huitlacoche (which they supply to Frontera Grill).