That looks like phragmites to me as well. I just cut a few in Salt Lake City today, just to see how far along it is in maturity. Not ready. In the northern part of the country there is no second year of growth on the culm of phragmites. Winter kills it and it starts anew in the spring. If you wait until just before the first frost should arrive or within a week after the first frost to cut, you can make some decent arrows from that. Providing you're not shooting a 100# war bow that is. My arrows are all phragmites and hold up well with my 60# longbow. Oh BTW, don't bundle them to dry. Just lay them out flat somewhere out of the way where they can air out but not get stepped on or broke. Just my 2 cents.
Josh