I also have this problem this year. I ascribe it to Bortrytis. Some of the lilies were freshly planted. Perhaps the fact that the roots are not fully developed , contributes to their reduced resistance. The late frost we had was not helpful either. Trumpet lilies are particularly vulnarable. If the bulb is not rotten, it should return next year. Some of mine which had this problem last year returned.

It has happened to a lot of mine this year also. We did not get our usual Spring it was hot and dry. Followed by extreme heat and dry. It has happened before. Let them build up energy from the leaves do not cut them down they will come back next year. Will probably be bigger because they did not use the energy to bloom this year.

Thanks for the replies. If the affected lilies go the route of the bottom lily in my picture, I will lose a total of 6 Lilies, all but 1 of my newest round of lilies is affected.

Aime