is it to late to plant a food plot in the woods thats not that big for september?

Im just getting mine done. There is still time. If you wait too much longer you would be better off waiting until the fall.

depending where your at you can wait till mid may

Your location is KEY. I also wonder why you wouldn't want a fall/late summerplanted annual instead? A fall planted annual will be FAR more effective as a "hunting plot" then nearly any Spring planted plot.