Beginner Gardening: Fatsia Japonica yellowing new leaves, 1 by monkapotamus

monkapotamus wrote:
I got 2 fatsia plants last year, and they made it through the winter and seemed to be doing well, but now they are getting a lot of yellowing leaves. I'm puzzled b/c it is some of the bigger ones and some new growth, but even other new leaves look healthy.

I looked into nutrient problems and it seemed like maybe an iron or sulphur deficiency, but I can't tell which -or if it is either- for sure.

Any ideas?

I'm in 7b. The soil was clay but I amended it a LOT and thought it was enough.