I don't think I'd want to emulate commercial growers who use high rates of fertilizers to get heuchera leaves to be as big as possible for resale. In fact, I wouldn't consider having bigger leaves a sign of better, optimal or healthier growth, only that it's been artifically pushed to grow as big as possible in a restricted container, perhaps even at the expensive of healthier roots.
I am trying everything and reading everything because I love the plant and have not had the success that I think I can/should get.
Have you checked out the data from the Mt Cuba heuchera trials in Delaware? It's near both of us!
http://www.mtcubacenter.org/pl...
http://www.mtcubacenter.org/im...
This research center found that the winter survival rate of heuchera depended signifcantly on the cultivar. Certain cultivars, while pretty, just weren't very vigorous.
