I'm not sure but I would say it's lacking something in the soil. Fertilize it with something low in Nitrogen, but I would fertilize it with something as soon as it is showing signs of recovering from the winter.

Happy Gardening, Marian

I planted my I. lazica in dappled/deciduous shade because I read that it prefers shadier conditions than I. unguicularis. It sits over the top of a culvert so the rain water all runs down that way, but the drainage is also great. Gets no extra water during drought. Mine isn't full of blooms like some pictures I've seen, but it has bloomed reliably every spring for the past 3-4 years. I think it took ~2 years to settle in before the first blooms -- the first winter was kind of rough because the deer kept yanking it out of the ground and I had to replant it several times.