Dave, I buy my rye at the local farm Co-op. Same place I get seed. At least in my area it is never perrenial rye but that doesn't matter. I plant it mid August, it grows good for the deer season by mid Sept, it goes dormant for winter but the great thing as compared to wheat and oats is that it stays perfectly green even under snow, then next year it goes to seed. Actually, lots of times it produces enough seed that I can just till one crop under and I get new growth. Even though is is annual rye our normal practice is to plant one year and harvest the next.
