Where to see and buy

• Ashwood Nurseries Ashwood Lower Lane, Ashwood, Kingswinford, West Midlands DY6 0AE. Tel 01384 401996, ashwoodnurseries.com

• Burncoose Nurseries Gwennap, Redruth, Cornwall TR16 6BJ. Tel 01209 860316, burncoose.co.uk

• Cambridge University

Botanic Garden 1 Brookside, Cambridge CB2 1JE. Tel 01223 336265, botanic.cam.ac.uk

• The Place for Plants East Bergholt Place, Suffolk CO7 6UP. Tel 01206 299224, placeforplants.co.uk

• The Savill Garden and Valley Gardens Windsor Great Park, Windsor, Berkshire SL4 2HT. Tel 01753 860222, windsorgreatpark.co.uk