By Cmmunsey
California,
United States 
Hi! I have a potted Abilene Clematis. I have the pot in a somewhat shady area. The plant is beautiful and heavily loaded with flowers. Last year, it's flowers were pink, but this spring, the flowers are all green. Do you know why this is? Thank you.
7 Apr, 2014
Depends on whether the flowers are perfectly formed, but just all green, or whether they're distorted and green/patchily green.
If the flowers are perfect but just green, that's something called (unsurprisingly) Green Petal - no one's certain of the cause, but it does seem to be associated with colder than usual weather just prior to flowering. Abilene produces another crop of flowers later in the season, and those (if the problem has been Green Petal) should be pink. Sometimes its just the first flowers which open that are affected, and subsequent ones in its first flowering of the year are not.
If, though, the flowers are distorted as well as green, that's Green Flower, and that means you need to dispose of your clematis as quickly as possible if you have other clematis around and about. Its not a condition which can be treated or cured, unfortunately, and it will infect other clematis.
7 Apr, 2014