Where can I get a detailed planting schedule for a wide variety of both Annual and Perennial Spring flowers that relates to zone 8?
Spring flowers in Zone 8 get planted outdoor now. Started indoor about 2 months ago (but it's not too late for a late bloom). Hopefully we don't have another snow in april kinda year, that just messes us all up.
I'm in STL. I'm frost free May 10. But some now say we are May 5. I started some of my perennial & pansy seeds as early as Feb. 7. Local nurseries are a good source to ask about your frost free date. Knowing that will help you read the seed packages on when to plant next year.
You can plant zinnia seeds still. Or Rudbeckia that will bloom next year. What plants are you thinking about? I know there are other seeds you still can plant that may not bloom this year (perennials). Let's see what the other will say.
In my zone 8 area the Frost Free date is around March 15th.
In my 8B, frost on 5-1 is not at all unusual....we're looking at at least a 6 week window for dates of last frost in Z8s :)