Howick is perhaps best known for Silverwood, the woodland garden started by Lord Grey in 1930. There is an extensive collection of mainly species rhododendrons which is still being added to, with a few of the better hybrids like 'Loder's White', 'Penjerrick', 'Princess Alice', 'King George', and a number of red ones derived from Rh. griersonianum. The large leaf species include mature specimens of Rh. falconeri, rex, calophytum, montroseanum, fictolacteum and macabeanum with young plants of grande, sino-grande, and kesangiae. Other well known ones are decorum, augustinii, sutchuenense, campylocarpum, fargesii, williamsianum, rubiginosum, insigne, and reticulatum, all from good forms. Tender species not often seen on the east coast include fragrantissimum, griersonianum, crassum and facetum.

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.

He found many other plants which flourish here and they include Eucryphia from Chile such as glutinosa, and cordifolia (sadly, we lost a large tree of the latter in a storm in 1997, squashed with a mature Chilean Firebush, Embrothrium coccineum, by a falling Spanish Chestnut), as well as 'Nymansay' (a hybrid of the two), and lucida and milliganii from Australia.They all have lovely white flowers in high summer. There is a fine specimen of Clethra delavayi from China with racemes of white flowers in July, and two good Drimys winteri from Chile flowering in May. Crinodendron hookerianum with its red lantern bells in July is also from Chile, while Hydrangea, Mahonia, and Magnolia thrive. We are particularly proud of two magnificent Magnolia campbellii at the east end of Silverwood, which are seventy five years old, 15m high, and covered with pink/rose coloured flowers in late March or early April most years; some years they have a rest and flower less vigorously. Magnolia wilsonii, sinensis, mollicomata, denudata , kobus, watsonia, stellata, salicifolia are all represented in the garden, as well as some hybrids. Apart from acuminata, the American magnolias do not tolerate our summers.

He was particularly fond of Cercidiphyllum japonicum, a beautiful tree from China and Japan, with delicate almost round leaves in spring which turn a lovely yellow/pink/rose colour in autumn, giving off a characteristic strawberry-like scent which can permeate a whole area around them; there are a number in Silverwood, and elsewhere in the garden.

Equal attention has been paid to ground cover, particularly by Lady Mary over the last thirty years and there is a wide variety of herbaceous material. Hellebores appear early and primroses follow quickly with lungwort, heucheras, dentaria, euphorbias, trillium, and many other woodland plants. Later on there are many Primula, particularly sikkimensis, florindae and viallii, with a varied mixture of home grown candelabra hybrids. In most years, we have a lot of the Himalayan poppy, Meconopsis. The blue ones include Meconopsis betonicifolia, grandis, (with a few white ones of both), and Lingholm, while home grown plants of the monocarpic napaulensis can be yellow, rose, pale blue or white, and up to six feet high; the much smaller yellow dhwojii and blue quintuplinerva are interesting but not long lived, while the small red punicea from China only lasts one year and has never yet produced viable seed here. Ourisia from New Zealand is another flourishing herbaceous plant in a number of forms, as are Smilacina, Smyrnium perfoliata a curious biennial from Greece, and Dactylorrhiza majalis from the orchid family. At the south-east end of Silverwood, just where the path comes to the bridge over the road, there is a young Chusquea culeou, a bamboo from Chile which appears to be vigorous and ornamental.

After the bitter winter of 1963, Lord Grey & Lady Mary planted many yews on the north side for shelter. Other and newer shelter belts have now grown up, so some of these yew clumps are being taken out and the ground being incorporated into the woodland garden.

While the shrubs may be quieter in July and August, there is still much to be seen; the eucryphias alone are worth a visit in August, and the hydrangeas as well in September, before the year ends with a good display of autumn colour, weather permitting.