I'm no expert on impatiens, but I wonder if fertilizing with bonemeal, or a phosphate rich fertilizer(no nitrogen), but the phosphate is supposed to help boost blooms, would help. I have a pot of New Guinea Impatiens- two different kinds. Both are growing well, but only one has flowered, and not that well. I have some bonemeal, and I think I'll put some in the blender with some water, then maybe heat and cool it and then try watering with it to see if it helps..I'll let you know how it does...

I did fertilize the Impatiens I started from seed with some all-purpose time-released fertilizer when I transplanted them. I think it was by Schultz. I may have added that to some of the Impatiens I bought as plants too, when I planted them. But last year, they did fine without any fertilizer. They were billowing out of the flower beds. Unless their New Guinea Impatiens, they really don't need much other than good soil and water. (Did you make sure your soil had a blend of topsoil and manure when you prepared them? I would think that's all Impatiens need)

impatiens are light feeders,and too much nitrogen will reduce flowering. On the other hand, if you do not fertilize, and there is not enough phosphorus and potassium in the soil, you may not get many flowers either.

What you can do, is to buy a bottle of 0-10-10 and fertilize your impatiens with this.

I normally fertilize my impatiens lightly with 14-14-14 osmocote in early spring, and then water with 0-10-10 approximately every 30 days.