Thanks for posting these. I have some thoughts, mostly on the first image, that I'd like to share with you.
First of all, I found this image slightly disconcerting at first glance. Clearly, the image reflects the symmetry of the garden but equally clearly the lower half (the pond) and the upper half (the hedging) are not symmetrical about the same axis. Your later post of the whole of the garden made clear why, but initially it threw me. Seeing the symmetry in the lower half, my brain wants to see it as well in the upper half and the lack of it is, as I say disconcerting. There's nothing much you can do about it (short of sneaking out at night with a spade and replanting the hedge
), but on the other hand that little note of visual challenge is perhaps a good thing forcing the viewer to look again.
My own inclination would be to crop out a chunk of the bottom of the image. There is nothing going on in that large expanse of water in the foreground and I feel it distracts from the more visually interesting elements. I would crop so that the two edges of the pool intersect the bottom corners of the frame which would get rid of the empty space and provide a nice lead in to the frame. One potential downside of this is that you end up with a more or less square frame. If that's an issue you could also crop down from the top to just above the top of the tree which would give you something close to 4:3.
I think given the difficulty of the light at this time of day I would try to soften the contrast and boost the dark and shadow areas - I'm not sure if this can be done in the programme you are using. I'm using LR3 and these can all be tweaked individually in the Tone Curve panel.
The other thing I would do is work on the colours. The green is very dominant and it's getting most of the sun so I would be inclined to reduce the saturation and luminance on green/yellow just to ease the impact on the eye. I would also try to boost red/orange to bring up the colour of the flowers and the reflections in the pool. I would also boost the blue saturation a little to bring out the blueness of the sky reflected in the pool. Again, I'm not sure how possible this is in your software but in LR3 hue saturation and luminance can be individually tweaked in the HSL/Color/B&W panel.
I think this is a good example of a picture taken in difficult circumstances that can benefit from a little work in post processing to bring out the details that attracted you to the scene in the first place.
On the second one I have little to add but to say that I agree with Nic - I think you could crop out some of the foliage on top - and with Andrew that a lower perspective which maintained the sense of movement downward but enhanced the sense of movement forward might be interesting.
Here's another version of number one for you to consider that I did with LR. Let us know what you think.
http://www.flickr.com/photos/olliinmunich/5643119820/