Sequoiadendron giganteum (Lindl.) J.Buchh. (Cupressaceae)


Giant redwood

The Botanic Garden in central Oxford had been in existence for more than 200 years before the first seedlings of Sequoiadendron giganteum were planted at the Harcourt Arboretum (part of the Botanic Garden). We can be sure of the age of our trees because in the late 1990s one was struck so violently by lightning that it had to be felled thus enabling us to count the rings and confirm that is was planted around 1855 - the year after the first seedlings were sold by Messrs Veitch for two guineas each. Lightning has now struck four of our trees but three could be left standing and have subsequently grown new leading shoots. There are no records of this species being blown over in the UK, which is perhaps unexpected since its timber is too brittle to be of any use except in shingles and rough fencing.

The fact that the timber is of little use did not stop the European settlers in California from setting up saw-mills and cutting millions of feet of lumber. In 1878, Sir Joseph Hooker, Director of the Royal Botanic Garden Kew, prophesized widespread felling would drive the giant redwood (or big-tree, as it is sometimes known) to extinction before 1900. Giant redwood would then have the sad distinction of having been discovered by Europeans and destroyed by Europeans in the same century. The fact that the species is not extinct is due to the efforts of men like American Frederick Law Olmsted (co-designer of Central Park in Manhattan) and Scotsman John Muir. The latter was born in Dunbar in 1838 but emigrated to America with his family at the age of 11. It is thought that it was Muir who convinced Hooker, and many others of the plight of the Pacific forests and their inhabitants. Some historians credit him with being the real force behind the establishment of national parks in the USA.

Giant redwoods are the bulkiest of all living organisms on Earth but they are not the tallest. That prize goes to the Sequoia sempervirens (coastal redwood). When one first sees a fully mature big-tree it is an unforgettable moment. For example, one tree in California has no branches on the bottom 120 feet of trunk and the lowest branch has a diameter where it joins the trunk that is greater than the maximum diameter of our largest specimen at the Harcourt Arboretum.

Further reading

Harvey HT et al 1980. Giant sequoia ecology. Scientific Monograph Series 12. US National Park Service.

Schmid R, Farjon A 2013. Sequoiadendron giganteum. IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1.

Timothy Walker