I would think they are good. I have been winter sowing for at least seven years. We put the perennial seeds out in weather in January and February and they sprout when it gets warm.
I have had great germination in older seeds.
If you want to test them, put some seeds in a folded paper towel and keep the paper towel wet. Last week I tested some spinach seeds. In a few days I saw "tails" coming out of the seeds.
These gaillardia seeds were four or five years old and they sprouted for me.
Don
