The first one is gorgeous. I like the second, but I feel like if I were shooting, I would have grabbed another angle besides head-on. I like the idea of the third, but it's kind of bottom heavy and maybe would have benefited from moving the camera down ever so slightly.
Technically, I'd say you're doing really well! Focus seems a little off in the third (to my eyes since they are drawn to the tip-top of the plant for some reason), but exposure and DOF looks good to me!
Number 1 is very cool, something a bit different, I like it.
I took something like number 2 at my house one time. Try lying on the ground (taking side on) and getting a horizon line in the background.
I managed to get about 70% sky and it made the soft, fluffy plant look big and overpowering.
Try 3 again with only the background of the green, the pink leaves take away from it.