Assistant head gardener Emma Thick and I are standing on the edge of the lake at Thenford House in Northamptonshire. The sun is battling against the odds, the handsome stone church of St Mary the Virgin is behind us, and a couple of geese are moseying around looking for trouble. More importantly there are trees everywhere and at every stage of life – from venerable oaks to newly planted acers – for this is one of the best stocked arboreta in the country.
Thenford is a very imposing house built in the 1760s to a classic Palladian design of two wings flanking a central block. It was bought by Michael and Anne Heseltine in 1976: the garden immediately surrounding the house was well cared for, but the woodland had
