Northern White Cedar is a native evergreen that is broadly pyramidal with a narrowing crown reaching 40 to 50 feet. Branches are horizontal and extend to the ground except on old trees where lower branches will usually be shed. There are frequently two or more secondary trunks.
Bark is reddish-brown changing to grayish-brown with age and with fissures and with shedding connected ridges on older trunks.
Twigs flatten in fan-like spreads. New twigs are yellowish-green maturing to reddish brown, with 3 or 4 divisions. Buds are so tiny they are covered by the leaves.
Leaves are evergreen and scale-like, opposite in alternating pairs, one pair flat - top to bottom of the twig, the other lateral pair keeled - side to side on the twig, which gives the twig a flattened look. Furthermore, there are two different types of leaves which are tightly appressed to the twigs. One type is about 1/4 inch long, flat and broad, with long points on the main twig shoots while the second type on the lateral shoots are shorter, 1/8 inch long with short points and appear folded and narrow. Leaves are aromatic, dotted with a gland on the back side.
Flowers: White Cedar is monoecious (separate male and female flowers). Female flowers are in cones which are solitary, up to 1/2 inch long, egg-shaped, green, with 4 to 6 pairs of scales of which only the middle pairs are usually fertile. Male flowers are very short pollen cones, reddish-green, tipped with brown and egg-shaped to rounded. These contain 2 to 6 pairs of sporophylls with each sporophyll having 2 to 4 pollen sacs. In early spring the sacs split open releasing the pollen. Both male and female cones actually begin to develop the previous Autumn, but do not put on much development growth until late winter.
Seeds: Female cones are carried upright on the branches and mature to produce two seeds in each fertile scale. They are oblong with two wings almost as wide as the body. The cone scales are reddish-brown, leathery, rounded top with a small spine of the tip. Cones will remain on the tree into the following year. Trees produce cones beginning around 6 years of age.
Habitat: Northern White Cedar grows in various moisture conditions from upland to swamps, but a cool, moist site with a limestone base is best. It grows well on well-drained upland sites but can become predominant in wet areas. In is somewhat shade tolerant. Trees are slow growing and can reach extreme age - several were dated in Ontario at over 900 years of age.
Names: Northern White Cedar is the type plant for the genus name Thuja, which is derived from the Greek thuia, the name for a Greek Juniper. The species name, occidentalis, means 'western' as differentiated from the old world plants. The author name for the plant classification, 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. The meaning of the alternate common name of Arborvitae, is explained below.
Above: 1st photo - Northern White Cedar leaf. 2nd photo - Stand of Cedars in the Woodland Garden. 3rd photo - Bark of an old trunk.
Below: Leaf Structure. 1st photo- Note the two different types of leaves that are tightly appressed to the twigs. One type is about 1/4 inch long, flat and broad, with long points on the main twig shoots while the second type on the lateral shoots are shorter, 1/8 inch long with short points and appear folded and narrow. 2nd photo - Leaves are dotted with a gland on the back side which produces the aromatics when leaves are crushed.
Below: Flower and Cone Development: 1st photo - Male cones, early spring. 2nd photo - Female cones, early spring. 3rd photo -Female cones enlarging.
Below: 1st photo - Summer cone development. 2nd photo - Mature cones from the prior year in springtime. 3rd photo - Prior year cones fully open before disintegration.
Northern White Cedar is not indigenous to the Garden area or to Hennepin County. Eloise Butler introduced the tree to the Woodland marsh on May 19, 1909 with trees provided by the Park Board Nursery and added 3 more in Sept. 1917, same source. Martha Crone planted some on July 31, 1933 - plants obtained from near Duluth - and again on Sept. 3, 1936 - plants obtained from Cedar Bog near Anoka, and others in 1950. The species has been in the Garden ever since. It has been planted over the years in a number of locations in the metro area primarily as a landscape ornamental.
Northern White Cedar is found in the NE quadrant of North America. In Canada from Manitoba eastward except Labrador and Newfoundland. In the U.S. from Minnesota and Iowa on the west, eastward to the coast and south as far as Tennessee and the Carolinas. It is considered threatened or endangered in 8 of the states. Some of the survival pressures on the tree come from deer which find the leaves very tasty. Within Minnesota its native range is the NE quadrant, south as far as Anoka and Washington counties and it is also known in Pope, Otter Tail, Winona and Houston counties. This is the only species of Thuja found in Minnesota. There is only one other species, T. plicata, which is the Western Redcedar, widely used for lumber where rot-resistance is needed.
Uses: There are over 120 named cultivars of this plant for use as ornamentals. They are widely planted in areas not originally native. White cedar wood is naturally decay resistant and is used in construction where exposure to moisture is expected such as fencing, decking, poles, etc. In a home landscape where deer are prevalent it may need winter protection from deer browsing.
Botanist Francois Michaux (son of Andre) wrote in his North American Sylva in the 1820s: "The perfect wood resists the succession of dryness and moisture longer than that of any other species, and for this quality principally, as well as its extreme lightness, it is preferred at Baltimore and Philadelphia for shingles...The houses in those cities, as well as in New York and the smaller circumjacent towns, are covered with them; they usually last thirty or thirty-five years. The superior fitness of this wood for various household utensils has given rise, in Philadelphia, to a distinct class of mechanics called Cedar coopers, and a great number of workmen are employed for the domestic and foreign market. They fabricate principally pails, wash-tubs and churns of different forms. This ware is cheap, light and neatly made; and instead of becoming dull, like that of other wood, it grows whiter and smoother by use. The hoops are made of young Cedars stripped of the bark and split into two parts." (Ref.#26D)
Historical information: White Cedar is considered the first native tree to be introduced into Europe. The French explorers under Cartier first found it in Canada and due to the miraculous properties of the tree (as explained below), he sent plants back to France where by late 1536 it was growing in Paris in the royal garden of Fontainebleau. It reached Britain in 1566 where it grows well on the Western Coastal hills. The twigs are known to have been used to produce a tea for the treatment of constipation and headache. Tea prepared with the leafy twigs and the bark is high in vitamin C and such tea saved the crew of explorer Jacques Cartier from scurvy in February 1536. His 3 ships and 110 men, having sailed from St. Malo to Stadacona, (The present site of Quebec) were ice-bound during the winter of 1535-36 while trying to find a northwest passage to China. At the time scurvy was not diagnosed. Cartier wrote:
The said unknown sickness began to spread itself amongst us after the strangest sort that ever was either heard or seen, insomuch as some did lose all their strength, and could not stand on their feet, then did their legs swell, their sinews shrink as any coal. Others also had all their skins spotted with spots of blood of a purple color; then did it ascent up to their ankles, knees, thighs, shoulders, arms and neck; their mouths became stinking, their gums so rotten that all the flesh did fall off, even to the roots of the teeth, which did also fall out. (Alan Gurney, Below the Convergence.)
Cartier wrote that the tea provided an almost instant cure. The Indians called the tree Ameda or Hanneda, and it is thought that this was undoubtedly the Northern White Cedar and from this comes the Latin name Arborvitae - the tree of life. The tea, while good for curing scurvy or rheumatism, was not considered palatable by some. Thoreau wrote:
"This night we had a dish of arbor-vitae, or cedar-tea, which the lumberer sometimes uses when other herbs fail, but I had no wish to repeat the experiment. It had too medicinal a taste for my palate. (from The Maine Woods)
The leaves and twigs produce a camphor-like oil, which may be useful as a salve but is toxic if taken internally without dilution and reduced to small quantities. The Minnesota Chippewa used the leaves along with other ingredients to make a cough syrup. (Refs. #5, 7, 20).
Another northern tree which provided a way to forestall scurvy was the Black Spruce, Picea mariana.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"