Why don't my Impatiens Seeds Germinate?
There is a fungal disease called 'Impatiens Downy Mildew' that has affected Impatiens walleriana and we do not recommend planting them. The fungus is favored by cool wet weather and symptoms were also seen in hot weather. Look for stunting and leaf and flower loss leaving green stems. Spores may overwinter in the soil and be a source of the disease next year. New Guinea impatiens are resistant. See our website for more information http://extension.umd.edu/hgic/invasives/impatiens-downy-mildew
Consider planting wax begonias, Angel Wing begonias, coleus, and torenia.