Most grass seeds are new each year because suppliers want the product to sell out of the stock and not have to retest the seed. However, grass seed labels are required to include certain information, including the Lot Number, the test date, and the sell by dates. The Sell By Dates will actually vary from state to state. Our current stock of Pennington Annual Ryegrass Grass Seed is from this year and has a Test Date of 3/2017 with a sell by date of 3/18 for AZ.