Wonderful article on Sissinghurst
An article from the NY Times titled: "Modernizing an English Garden" - fabulous read!
(Excerpt) "Can a modern family make a home among hordes of tourists under the watchful eye of EnglandÃ¯Â¿Â½s National Trust? The grandson of Vita Sackville-West and Harold Nicolson attempts to bring Sissinghurst, one of the most famous gardens in the world, into the 21st century."
Here is a link that might be useful: Bringing Sissinghurst Into The 21st Century