Cambs CB4 4ZZ; tel: 01945 588522.Clematis'Princess Diana:' Thorncroft Clematis Nursery, The Lings, Reymerston, Norwich, Norfolk NR1 4QG; tel: 01953 850407.Tulip 'Lady Diana:' In garden centres now.Aster'Diana: Old Court Nurseries, Colwall, near Malvern, Worcs WRI3 6QE; tel: 01684 54...