Coffee Trees Suffering from Chlorosis, help?
So I have eight or so coffee trees in clay pots, currently indoors in a west facing window. They have some supplementary lighting for when the days grow short (zone 6). They were doing fantastic all summer long with dark green growth, however I have come to a point where all of them are exhibiting signs of chlorosis. The worst case has its image uploaded. The soil is slightly acidic; I use a potting mix of peat and cactus soil. I water as frequently as the soil becomes dry. Everything points to an iron deficiency, but I hear that soils are typically naturally rich in iron.
Help? Ideas? I'd hate to see my coffee army slowly wither and die.