Impatiens are actually tender perennials but are generally grown as annuals. They need the following:
Sun -
Too much sun will wither them fast. Plant in a shady spot that gets half a day or less of full sun – preferably morning sun.- If you let Impatiens dry out too much they will wither quickly and die. One negligent day will do it. Make sure to keep the soil moist at all times.
Water