New Guinea impatiens flowers continuously all summer and into fall with little effort other than watering. No deadheading is required. Just keep them moist. Best in part sun.
New Guinnea impatiens is ideal with 2-6 hours of sun, or at least several hours of dappled light. We don't find that the plant flowers well with fewer than and 2 hours of sun. Although it will grow in full sun, new guinea impatiens doesn't like the heat and will require very frequent watering. At least a little shade during the hottest part of the day is ideal.
New Guinea impatiens should be kept moist but not soggy. New Guineas are light feeders--if you use fertilizer, use it at half the strength recommended on the label.