Trees that move, children's ghost/horror story from 1970s

[H]

This would have been a book, or a shorter story in an anthology from a major publisher in the UK (Penguin maybe) from the 1970s.
There was a house with lawns, paths and clipped trees looking like cypress, leylandii, box or poplars - very formal shapes. As time went on, the trees began gradually moving closer and closer to the house in a sinister way. There were a couple of pictures showing the scene, which is how I remember the clipped shapes of the trees. I can't remember the author or the ending, but another friend remembers the same story so I know it did exist!