Green Island is a twenty-acre garden at Ardleigh, laid out by designer Fiona Edmond from 1996 across a triangular patch of former woodland. It runs through a series of contrasting rooms — Japanese, gravel, water and seaside gardens, with shady woodland underplanted for spring — and holds National Collections of camellias and hamamelis. There’s a nursery and tearoom. Open on advertised days with an admission charge, so check dates before setting out.