I understand that black cedars are cultivated from white cedars. If this the case, can black cedars be found in the wild? If so, how would you tell the difference between white and black? Thank you!
Thank you for contacting Toronto Master Gardeners:
Our website Toronto Master Gardeners has information on Black Cedars versus White Cedars: Black Cedars
As the Conifer Society (from the above entry) states, the origin of the cultivar Black cedar (Thuja occidentalis ‘Nigra’) is not known and it can be distinguished from the white cedar “by its exceptionally dark-green foliage.” The entry goes on to say, “This is an rather old cultivar in the nursery trade that unfortunately is of unknown origin. It is thought to have originated in the USA in the 1930s. L. H. Bailey formally described it in his 1933 book, Cultivated Conifers in North America.”
Its distinguishing features are: it is a compact conical selection of eastern arborvitae with exceptionally dark-green foliage that retains its green color in the winter in cold climates. You can also distinguish Thuja occidentalis ‘Nigra’ as it is smaller tree than the white cedar, has dark green foliage year-round and the bark is dark reddish-brown. Black cedars are columnar shaped with a mature height of 15 to 20 feet with a dense growth.
Cultivars will only produce the same results if propagated vegetatively. Some cultivars may be sterile and not grow from seed at all. This website will provide information on why you may not find the Thuja occidentalis ‘Nigra’ in the wild. Cultivar versus Variety