Some years ago I ordered lily seed from the Scottish Rock Garden Club seed exchange. I was told it is the best way to avoid the lily beetle. They are not quick to get to decent size but they are extremely beautiful when they get there.
Here are the flowers of 3 martagon types flowering in pots in the greenhouse. I'll repot in the late summer and maybe put in the rock garden next spring. These are a white martagon, Lilium martagon cattaniae and the amazing L ledbourii.