I have had a crystal palace geranium for several years, always had beautiful lime green leaves. All of a sudden this summer I got one branch with dark green leaves. Anyone know why this would happen? Hard to see in the photo, but it's in the bottom left area.
cyndyeo your plant is showing chlorosis , this happens when the soil is a bit into the alkaline side (alkaline soils) adding iron or iron sulfate may help you to reduce the chlorosis (yellowing) of the foliage, also the yellowing of the leaves could be due to a deficiency of nitrogen, a bit of organic fertilizer will do the trick.
thank you for your suggestions, but I think you misunderstood the problem. This plant is supposed to have the yellow/chartreuse toned leaves with darker green zonals. Then all of a sudden I got one branch where all the leaves are the darker green of the zonals, there's no yellow green. I'm trying to get the yellow green back. So maybe I have the opposite problem, my soil is too acid? And I did fertilize this plant a couple times over the summer with Espoma flowertone, maybe too much?
Sometimes when plants have been chosen for the unusual leaf color, they will revert back to the common color. I have read where you have to either give it more sun or less sun depending on the specific plant. For the geranium, I am thinking it may need more sun. Sometimes people cut out the common foliage, because they want the plant to put out more of the unusual color.
I lean toward not getting plants that have the unusual, uncommon color on leaves, because they are usually more costly, and they often revert back to the common color.
Thanks for your reply, I actually did cut off the branch with the dark green foliage last fall, and so far all the new growth is varigated like I want. So hopefully I've seen the last of that. But I do think my fancy muscari has reverted back to solid purple, either that or the lighter blue ones died out.