cerinthe seeds

I have quite a few cerinthe purpurea seeds that I collected last year. Does anyone know how deeply these large seeds should be planted?

 

I don't know how deep they should be planted, but mine are doing just fine after I planted them around 1/4 inch below surface in pots to get them started. I've just potted them on and they're around 6 inches high.

Next year I'll try a few directly outdoors, probably around the same depth.

 

Thanks, I think I'll plant mine directly outside.