The later you plant, the more you have to look at them as getting a start on being first year plants next year. However, as long as you don't kill them it is hard to think of time in the ground as wasted. All you might lose is a few bucks and a little time with a garden trowel. If they grow, you have a head start on getting them to the size that will produce a crop for you. If they don't, well, at least you tried,. I planted some rather late last year. I ended up bringing some of the buckets inside under grow lights to see what would happen. I got pretty good growth in my basement. (I also drowned a few of them, purely exuberant "operator error"). Those that I did not drown are off to an okay start.
I just ordered from these folks for the free shipping. http://diybrewing.com/beer/ We'll see when they come in. I got a bunch from these folks earlier. http://www.baderbrewing.com/store/home.php?cat=408. They seem to be fine. I bought from Freshops last year, and theirs did well. I got one rhizome from Midwest this spring that was DOA, too loosely packed and knocked around, with it's bud broken. All the rest have been fine.