There isn't a registered daylily called Predictable You. Does yours match 'Unpredictable You' or is it completely different?
Daylilies are said to need a minimum of six hours of sun, it's possible that is holding them back compared to if they were getting more, but it could also be nutrition, watering etc. I can't suggest a home test kit as I don't know what is available to you there but have you looked into testing by your local extension office? Some extension tests are inexpensive enough that it's not worth doing a home test, and should be more accurate. It's more expensive in some areas though.
Edited to add it looks like you'd be referred to a lab by the extension service, maybe you already knew that:
http://m.extension.illinois.ed...
