Broke my hand so I apologize for choppy sentence structure. Live in Colorado. 300+ days of sunshine. Planted Impatiens in a bed I made around a tree in front yard. Used 2 bags of Ecko Compost and 4 bags of gardening soil. Seems to be more compost overall than soil. Planted the impatiens about a week ago. Receive sun most of the day, but is relatively filtered by tree. Water every other day for 10 minutes. Problem is the flowers are wilting, seem to get black around edges and are very small. I see new buds, but no healthy new flowers. Advice? Diagnosis?