Wisley has always had a good collection of heathers, but the National Plant Collection was established about 10 years ago. This collection now exceeds 1,000 accessions, representing 25 species and subspecific taxa, and over 1,000 cultivars. As well as Erica and Calluna, there are representative specimens of Daboecia and Bruckenthalia. Each year new cultivars are added, many from Germany, the Netherlands and the USA. Links are maintained with many other institutions and nurseries, with regular exchanges of material of mutual benefit.
Favourable growing conditions have helped the collection to flourish. The collection, which occupies much of Howard's Field, beyond the Pinetum at Wisley, provides a fine spectacle for visitors each year. Strong links are maintained with the Heather Society and other institutions.
The entire collection is catalogued in the RHS Horticultural Database, and steady progress is being made in creating herbarium and photographic records of the collection.