Not related to lavender frost, I used to have several Pink Frost trumpet seedlings in my field, where the weather was good enough to show the pink. I did not have many seedlings of Lavender Frost, and only saved seed from backcrossing a similar seedling to its mom, the few seeds I moved with me were all I got from there for lilies, except for the ones you generous people send me.........
I mostly saved Aurelian and American hybrid seeds, those have been the fastest growers for me (except for some of the Western American species that are deathly slow, like L. columbianum and washingtonianum)