Love the color on 'Cardinal's Roost' Jim. Mine still has no leaves, but nice firm, green pb's so I am holding out hope for it.
For other plants, iron is good for greening up the foliage, but . . . sounds kind of drastic for orchids to me. Mine get a lot greener if I just reduce the amount of light they're getting.
The Orchid Plus that I'm feeding with these days has a .2% iron component.
Now, here's a plant that needs some iron! A gorgeous - totally anemic - tree peony in my daughter's garden in Salt Lake.
