This is a nice little clicker. Seems to have quite a bit of charm. But boy is it stingy with the advancement! I'd recommend ramping up the cost of plants much less slowly, or better yet, letting the player ramp up $/sec or $/click much faster, as that would probably feel more satisfying. As it stands, it got very dull very fast, with way too many clicks required to plant a plant. Unless you intend this to be one of those "walk away from it and come back later" type clickers, it would help to reduce the aggressiveness of those curves.
It really needs a save game feature (especially if it's going to be a "walk away and come back" type game).
The keyboard support is a nice feature. Pressing space bar on a laptop is much preferable to clicking a trackpad. I'd like it if I didn't have to click on what I wanted the space bar to do each time - perhaps you can instead have keyboard shortcuts for calling up the menu or doing other things?
It seems like clicking the portrait of the witch should do something, like give a temporary multiplier to the plant gains or yield a different currency. (Or just play an animation.)