I have a spinach seedling popping up under my grow lights. The seeds are from 2001. Its come up before my newer seed! My Bok Choy, toy Choy is from 2013 and it always germinates. I've got 2 delphinium seedlings from seed I saved in either 2013 or 2014. Not great germination rates but I never plant more than 5-6 seeds anyway. Don't have space for more than 2-3 plants of each variety!
