My clematis (not sure what type yet) has made a good recovery this year, but there haven't been any blooms. The growth has been fantastic, but recently the leaves at the base of the plant have started to yellow. The temperatures have gotten much warmer and the lots of rain has turned to no rain. I've been watering it but that doesn't seem to help. I can't tell if I've over fertilized, under fertilized, over watered, under watered, etc. I did spray for bugs (hand pump spray bottle). How can I know what is causing this?