we seem to be getting more leaf than flower, when we got them four years ago they did very well, but the number of flowers has gone down hill ?.
Callas like moisture and sun which is a tough combo in some areas of the country. I've always grown or seen them in the ground and they are relatively problem free. This makes me suspicious that 1. that pot is too small or 2. the soil is spent and there isn't the energy for blooms. Over 4 years, the bulbs (really rhizomes) will have grown quite a bit. Do you lift and divide these annually? This isn't necessary for in-ground callas but I would do it with potted ones. Then refresh the soil.