I have planted my New Guinea impatiens in the same spot for several years with great success. This year I am getting no blooms just healthy looking green foliage. Why might they not be flowering?
New Guinea Impatiens
Certified GKH Gardening Expert
It could be due to excess Nitrogen. Too much Nitrogen or over fertilizing can give you nice lush plants, but inhibit flowering.
When fertilizing use a low Nitrogen formulation.
You can add some Phosphorous to encourage flowering, Bone Meal is a good way to do this.
Here are some links with more information.