Back in April we had an unusually late frost..just when most of my lilies were starting to poke through the ground. Most seemed to recover fairly well but I noticed that a few were discolored. Now the same plants seem to have some streaking/motling of the leaves. They don't seem to be stunted and the growth seems pretty strong. I'm starting to think that maybe it's a virus and not frost damage. I'm not sure what to do. How long should I wait before I start ripping things out...If I wait too long will it spread to other plants?
Possible Virus
Don't be too hasty in pulling plants, you might only have a nutrient deficiency. Can you post a pic of the questionable foliage?
For the time being, get control of sucking insects such as aphids and thrips, if you have them.