I was given a hanging basket for Mothers Day. This was Double Impatient. I noticed that the leaves where black at the tip on receiving it. Since then all the leaves have gradually turned yellow and they drop off. There has been no new growth on the flower. Now it has tall leafless stems and few flowers. It is kept in a Westerley position. Morning sun only. It has been watered carefully and fed twice. I have also grown my own hanging baskets which are great. What could be the problem with this hanging basket.