Charlie,
These are all too tight IMO.
1. Too tight and probably need sun to light up the trees. Unfortunately this is how it is with landscape photography. You need to wait for the right time and weather.
2. Same as 1.
3. LIght wise, i think it is pretty good. I still think it is not wide enough. I want to see the tip of the trees especially when you do portrait orientation
4. Subject isnt interesting enough
5. Best lighting of all. I can see different spectrum of green thanks to the sun. I think the horses hurt your frame. And same thing again, not wide enough. I need to see the blue sky.