seeds

I use T&M larkspur too and have found them to be reliable but if too dry try damping the soil again and they may come.
the other comment about some needing light is true though not for larkspur. You can sow the seed directly outside where you want them to grow but later in april or even may. I tend to do sweet williams in the summer as they can then be planted out in late summer and then they will flower next spring.
enjoy your garden john