Photoshop :: Fill In A Dotted Area?

it's regarding this image. Originally it was very dirty in the background (still is if you look at the striped mountains and cottage), and I've tried making it white by playing around a bit with the curve adjustments. Obviously the results weren't as white as I wanted them to be, so I decided to dodge some areas (on the other parts of this picture which I didn't include). Later on I decided to pick up the bucket tool.

It works very well, but now I'm having this problem. If you look at the red ground, it's all dotted. However, the bucket tool filled up some of these dots too, making the ground very thin.what I can do about this?how I can make the background white (the quicker the method the better!) in case the curve adjustment settings doesn't properly work?