We had an old tin of popcorn that we bought from the Boy Scouts fundraiser a couple years ago that was almost gone. This spring I planted a 2×2 square with a bunch of the kernels and was very surprised by the germination rate. I pulled out 5 or 6 for each one I kept.
Now they are getting close to being ready. The ears are a nice size, and most of the stalks have two ears. I peeked inside the husks of one ear, and I can tell it needs a few more weeks. We will dry this and have enough popcorn (and seeds) for another year.
The eaves of the garage in this picture are over 8 feet high. This is pretty tall corn.