An evergreen tree attaining a height of over 300 ft in the wild and already well over 100 ft high in this country, where healthy isolated trees form slender pyramids, furnished from base to summit with leafy branches. In their native forests crowded trees may have 75 ft or more of clean trunk. Bark of a rich brown-red, and of a fibrous nature, 6 to 12 in. thick in the giants of western N. America; young shoots and leaves not downy, arranged in two opposite rows. Leaves linear 1⁄4 to 7⁄8 in. long, 1⁄20 to 1⁄8 in. wide, terminated by a short abrupt point, very dark lustrous green above, with two broad stripes of white stomata beneath. On leading shoots the leaves are shorter and arranged all round the branchlet. Cones roundish oblong, 3⁄4 to 1 in. long, about 1⁄2 in. wide.
Native of California from Monterey northward, just reaching into Oregon, confined to a narrow belt near the coast where summer fogs off the Pacific are frequent and mitigate the summer heat and drought. The best development of the redwood is north of San Francisco, where the most extensive and purest stands occur, at altitudes of up to 3,000 ft. It was described by David Don in Lambert’s The Genus Pinus from specimens collected by Menzies in 1796 and introduced to Britain via Russia shortly before 1843.
Like its ally Sequoiadendron giganteum, this is one of the vegetable wonders of the world, having been measured around 350 ft in height in its native stands and 25 ft in diameter, though only on the alluvial soils where it thrives best. The largest trees are probably near 2,000 years of age, but maturity is reached at 400-500 years and merchantable timber is produced by trees only 100 years old. Old natural stands have yielded 300,000 gross board-feet per acre, and even one million on very favourable sites. Young managed stands, grown on a 100 year cycle, are expected to produce 350,000 board-feet per acre (Fowells, Silvics of Forest Trees of the United States, Agr. Handb. 271 (1965), p. 666).
The germination rate of redwood seed is low, but in nature such vast quantities are produced that this is of little account. The redwood also has the remarkable ability to reproduce itself by root-sprouts, which, on rich soils, spring up round the stump only a few weeks after felling and quickly develop their own root-system.
Redwood timber is highly valued for joinery and building; it is reddish, free from resin, light and easily worked; being very durable, it is also used for shingles, sleepers, piles and posts.
Most conifers from the coastal regions of western North America thrive excellently in this country, and the coastal redwood is no exception, but the best growth is attained in the rainier and more equable conditions of the Atlantic zone. Some specimens planted soon after the original introduction still survive, as do many of those mentioned by Elwes and Henry in 1908 and nearly all those listed in the returns to the Conifer Conference of 1932. Thanks to Alan Mitchell’s researches for the Forestry Commission we have abundant information on the rate of growth of the redwood in this country. The following is only a selection of the trees that he has measured recently; for a fuller list see his Conifers in the British Isles (1972).
Bowood, Wilts, pl. c. 1845, 105 × 20 ft (1975); Whiteways, Devon, 118 × 201⁄4 ft (1975); Leighton Park, Ackers Memorial Grove, nr Welshpool, 121 × 161⁄4 ft (1975); Bodnant, Denb., 133 × 141⁄4 ft (1974); Taymouth Castle, Perths., 130 × 221⁄4 ft and 120 × 213⁄4 ft (1974); Caledon Castle, Co. Armagh, 115 × 223⁄4 ft and 118 × 213⁄4 ft (1976); Curraghmore, Waterford, Eire, 102 × 21 ft (1975); Coollattin, Carnew, Co. Wicklow, Eire, pl. 1851, 117 × 21 ft and 124 × 21 ft (1975).
Younger trees, to show rate of growth: Blackmoor, Hants, pl. 1915, 105 × 12 ft (1974); Forestry Commission, Rhinefield Drive, New Forest, pl. 1955, 80 × 33⁄4 ft and 75 × 51⁄4 ft (1976); Forestry Commission, Alice Holt, near Farnham, Surrey, pl. 1951, 56 × 53⁄4 ft (1975); Wakehurst Place, Sussex, pl. 1920, 94 × 123⁄4 ft (1975); National Pinetum, Bedgebury, Kent, pl. 1925, 92 × 11 ft (1975).
As will be seen from these measurements, the coastal redwood grows well even outside the Atlantic zone. It is, however, rather tender when young, and is not suitable for places exposed to cold winds, nor for shallow chalky soils.
cv. ‘Adpressa’ (‘Albo-spica’). – Leaves only 1⁄4 to 3⁄8 in. long, loosely appressed (as on fertile shoots of the type); tips of young growths creamy white. Although sometimes referred to as dwarf, it is so only if leading shoots are cut out. Left to itself it makes a tree, e.g., 73 × 81⁄2 ft (1971) at Grayswood Hill, Haslemere (S. semp. adpressa Carr.; S. semp. albo-spica Veitch).
cv. ‘Cantab’ (‘Prostrata’). – Of semi-prostrate habit, with remarkably wide, glaucous, two-ranked leaves, not much over 1⁄2 in. long and about half as wide. It arose as a bud-mutation on a tree in the University Botanic Garden, Cambridge, and received an Award of Merit in 1951, when exhibited as S. semp. nana pendula – a name earlier used by Hornibrook for a different clone, not treated here and probably not in cultivation. It has also been grown as S. semp. ‘Prostrata’. It is an unstable variant, which sends up strong erect stems, one of which has attained 20 ft in the Hillier Arboretum, but retains the broad leaves of the original mutant.
For propagation, see Sequoiadendron giganteum.