I am having the same issue with what I believe are orientals, green viens and yellowing leaves, does the yellowing start in the upper most leaves for you? Is a Martigon a oriental lily?

Hi there. I would have to say that my martigon looked this way basically from the start of spring growth. Martigons are not an oriental; they are sometimes known as Turk's
Cap lilies and are beautiful. They prefer a more shady position and bloom before the Asiatics. Even in zone 3 mine is close to blooming now. They are very long-lived and a bit slow to become established. Their flowers are small and down-facing but a mature plant can have many, many flowers. There are many different varieties and are on the more expensive side as they are difficult to propogate. Oriental lilies do not do well here; we tend to treat them more like an annual or very short lived perennial. Hopefully someone can give us some advice about treating the yellowing foliage.