I like how there is a Vileplume nestled nicely in a flower pot. In a city such as Celadon, it's like the Grass-type pokemon equivalent of having a nice bench to sit on. Nice touch, Grass-type trainers should think to get a few flower pots for their Pokemon.
Oh, this is so nice-looking, I love the way you shaded it, and such a detailed background, too!
The only thing that bothers me is this weird sense of, uh.. disconnect(?) that I'm getting from the objects, like they're on top of the image rather than being part of it, not sure how else to explain it.
That aside, then I am totally digging it, and Leaf is pretty cool indeed~