Lord Grey was well connected in the gardening world, his uncle being George Holford of Westonbirt Arboretum in Gloucestershire (now the largest arboretum in the UK, owned and managed by the Forestry Authority), while Giles Loder of Wakehurst Place in Sussex (now an offshoot of Kew Gardens) was a great friend; a lot of rhododendrons were given to him by them from new collections being introduced from China and the Himalayas, but sadly he kept only the most rudimentary of notebooks, so we now have no accurate information on the origins of most of the old rhododendrons in Silverwood. Nowadays they flower from late March, which makes them vulnerable to spring frosts, until late May, continuing on into June. We are often lucky in avoiding frost, being close to the sea, but not always. Some of the rhododendrons are well worth seeing for their spectacular new leaf growth in June, which can be as interesting as their flowers, the best being Rh. kesangiae.
Apart from the well known and sweet smelling yellow azalea from the Caucasus, Rhododendron luteum and its hybrids, most of the other azaleas from America and Japan find our summers a little cool and do not always flourish; schlippenbachii and albrechtii from Japan are two of the best. Other woodland genera which were tried by Lord Grey but which didn’t really thrive were Enkianthus, Menziesia, and Stewartia; all like a good summer by our standards, but Pieris, Gaultheria, Vaccinium and Leucothoe on the other hand grow well. The Pieris in particular in May/June are lovely with their long racemes of white flowers, followed by young leaves coloured red to warn the insects not to eat them while they are poisonous, before fading into a pale green.