Is that Stowe Gardens?
#1 - colours are a little too rich for the overcast conditions - slight HDR? Reflection is nice, but the foreground grass isn't really interesting enough - perhaps a shot from much closer to the bridge, using
it as the main foreground, with the path leading away up to the second building, may have worked better?
#2 - suffers from a similar composition problem with the grass, although the leaning tree adds some interest, and the sky has done you a few more favours. Having had a very quick play with it, a mono conversion with some harder processing, and a tighter crop bottom left makes for a moody version, which I can post if you like
#3 - colours are nice in the grass, and the tower, and the sky too, but there's not really enough in the frame to hold the eye for long. I might've opted for a wide angle, distorted shot of the tower with some of the contrasty sky behind.
Overall, though, exposures are good, shots are sharp. Landscapes, as I'm still learning, are nearly always dominated by the light: warm/cold, time of day etc.