I went to this a while ago, in our glorious summer!, there was a terrential rain storm whilst I was on my way there (I got absolutely soaked). It was worth it though, it was such a beautiful place.
Here are some of the photos I took. The garden was amazing, so tranquil. The planting was by Piet Oudolf, if you don't know his work he is well worth checking out if you like natural planting. I went a bit crazy with the zoom, but am quite happy with the results.