I found this chart at http://awaytogarden.com/estimating-viability-how-long-do-seeds-last/
So. I'll be pitching my old onion, parsnip and parsley seeds for sure. And I'll be getting all new spinach seeds - maybe that's why we've had a problem growing spinach. I was trying to use old seed...
When I was going through my box of seeds, I realized that I had a bunch of herb seed that was aging as well. Here's a list of herb seed viability rates from The Herb Gardener: http://theherbgardener.blogspot.com/2013/01/seed-longevity-herbs.html
- Angelica - 6 months (21 - 30 days)
- Basil - 5 years (14 days)
- Borage - 4 years (14 days)
- Caraway - 3 years (18 days)
- Catnip - 3 years (30 days)
- Chamomile - 3 years (18 days
- Chives - 2 years (10 - 20 days)
- Cilantro - 2 years (21 days)
- Coriander - 4 years (21 days)
- Fennel - 3 years (18 days)
- Lavender - 2 years (21 days)
- Lemon Balm 3 years (21 days)
- Marjoram - 2 years (15 days)
- Mint - 3 years (30 days)
- Oregano - 4 years (30 days)
- Parsley - 2 years (30 days)
- Rosemary - 3 years (14 - 28 days)
- Rue - 2 years (21 days)
- Sage - 4 years (28 days)
- Summer Savory 2 years (28 days)
- Thyme - 3 years (21 days)