Here's what those same beds looked like today:
I'd say corn gluten really works. But take note: put it on regularly. It's recommended every four to six weeks, but I pushed it to about seven and I have little weed seedlings up out there. Just a few, but enough to be a pita. So I'd say shoot for every month and you'll be okay if you are a week late on your schedule.
If I remember, I'm going to try this again on the tomatoes to see if it works as well in the warm season. I certainly hope so!