It would be a good idea to have
candidum or
formosanum near your lilies. They can detect viral infection.
@Leftwood I live in a fairly isolated place and no one near me (and beyond) grows lilies or related species so it is possible for me to make a virus free garden if I grow everything from seed. I no longer keep hybrids, and they are (in my opinion) the main culprit of the infection in our gardens.
