I set a little guy(2 inch tall) in the ground April 26, he didn't make it.
Set the bigger plants out to harden on May 3rd. Planted them May 12.
So far so good. Thought a couple of them look as if they started to grow a bit today.
Frankly I think I could have gotten them out earlier, but they were too small and would have needed more hardening.
Last year I direct seeded in the ground, took a month for them to sprout(not till mid June) I had given up on them. Then they just started popping up. They were good producers, but late.