Howdy redbeard, I keep my seeds in the freezer in plastic bags wrapped in foil. Some of the have been around for years. I kept them at room temperature for a long time but when I decided to try my hand at growing, I did not get any to germinate. I placed them in the freezer for a few weeks and tried again. The second batch had a reasonable germination rate! I now keep all of them in the freezer until I need them.