On the suggestion of a friend we went to Leonardslee Gardens, Sussex (
https://www.leonardsleegardens.co.uk/ ). As you can see, in my photographs at https://adobe.ly/2Q2OUtU the flowers were absolutely gorgeous. There were huge numbers of visitors but I managed to exclude most of them from the photos.
If you decide to go it is cheaper to book on line rather than pay at the entrance.