I planted a pot of white and fuschia impatiens along with potato vines and salvia and they bloomed beautifully in the beginning. After a few feedings with Miracle Grow and plenty of water, the impatiens are coming in brown-tinged and sick looking. The potato vines are doing okay, and the salvia are slow to bloom. What could be wrong? Might I have a pot that isn't draining properly and they may be getting root rot? The plants get full sunshine in the early morning till about 11am. Any help would be appreciated as I've never had this problem before.