Trinity Tree of the month - the Giant Redwood
Posted on: 31 January 2024
This month we are bringing you one of our old ‘native’ tree species, Sequoiadendron giganteum, referred to as Giant Redwood or Wellingtonia. These are some of the most massive trees in the world, with the tallest living specimen standing at 84m tall with girths of 35m. They can live almost 3,500 years, making some of them the oldest living organisms on earth.
Trinity has one young specimen of Giant Redwood at the edge of the Physics Lawn, and a larger specimen located at Trinity Hall. The larger tree measures 36m in height with a girth of 4m and an estimated carbon storage of 8.7 tonnes. This tree is often subject to lightning strikes and thus damage, and to help protect against this we have a lightening strip installed. This requires regular inspection and extension as the tree grows. 
This species is now restricted to California, though this or a related species occurred in Europe in the Tertiary period. There is fossil evidence of a species of the related genus Sequoia from County Galway which dates from just before or at the beginning of the Quaternary period. These and several other formerly native species were eliminated from many temperate regions by the climate change brought about by successive glaciations in the Pleistocene. The trees are sensitive to moisture stress, thus future climate change is a worrying factor. However, Ireland’s predicated moist climate should provide a safe habitat.
The Giant Redwood is a member of the Cupressaceae and a gymnosperm which means ‘naked seed’ in Greek. It is the sole living member of the genus Sequoiadendron, though extinct species have been described from fossils. The tree is an evergreen with dense dark blue-green scale-like foliage. It starts out pyramidal in shape before maturing into a more conical form. The bark on mature trees is extremely thick and spongy, providing protection from forest fires. It is also rich in tannic acid, helping to protect against fungal and insect attacks. At the College Botanic Gardens, the spongy bark of both Sequoiadendron and the related Sequoia are used from our own trees to provide a potting material for tropical epiphytic orchids.
If you’re looking to explore some Giant Redwoods in Ireland, Giants Grove in Birr, County Offaly is a good destination. It was set up by Crann - Trees for Ireland to create the largest grove of Redwoods outside of California.
Credit to John Parnell, Michelle Murray and Stephen Waldren for providing this information and caring for our trees.
Media Contact:
Katie Byrne | Public Affairs and Communications | katie.s.byrne@tcd.ie | +353 1 896 4168