Although common in a few areas, hemlocks are quite rare across PEI. Many older barns and homes were sided with hemlock boards, but the wood is not as valuable as pine or spruce. No other plant in the province is as rich in tannin, and so hemlock bark was much in demand for tanning leather. Hemlock has a life expectancy of between 300-400 years. When large trees fall down, they take a long time to decompose and provide both nutrients and moisture to young seedlings.
Hemlock is one of our largest native trees, reaching a height of over 22m (70′) and a diameter of 1-1.3 m (3-4′). The small, flat needles resemble those of balsam fir, but are smaller and attached to the stem by a small, string-like stalk. The ends of the branches and leader also droop, unlike the balsam fir branches which grow straight out to the end. Because of this characteristic, older hemlock trees have a very round profile when seen from a distance, while fir are noticeably pointed.
Often found along streams, hemlock flourishes in areas of high humidity but without standing water. It grows best in rich, well-drained land, growing with yellow birch, sugar maple, red maple, white pine and red spruce.
Cones can be collected from the tree when ripe in late September and treated the same as red spruce. An easier method is to find a 4-10 year-old forest road that has been bulldozed through a stand containing good hemlocks. You will usually find healthy seedlings growing on the roadway. These transplant easily and can go into a shaded nursery bed, at 15-30 cm (12″) spacings depending on the size of the seedlings. In a few years you can use these transplants for your forest, stream side or home plantings. Placing rotted wood in the hole when planting out will make sure the seedling does not dry out and provide nutrients for future growth. Seedlings should be mulched well.
Hemlock seed is a preferred food for American goldfinch, boreal chickadee, ruffed grouse, pine siskin and red-winged and white-winged crossbills. Many other species of birds and mammals also eat the seeds, and snowshoe hare browse young shoots. Large, old hemlock are used by raccoon for dens and provide cavities and nesting sites for a wide variety of birds. Hemlocks also offer great cover and protection for both small and large birds and at Macphail Woods the largest hemlock contains a hive of honeybees that has overwintered for many years. As large trees start to break up and die, red-backed salamanders are common under the loose bark on standing trees. Amphibians can also be found under and around hemlocks that have fallen to the ground.
All efforts should be made to conserve this species, since it has been so heavily harvested on the Island. While it could be selectively harvested from areas that have sufficient amounts of hemlock, these types of woodlands are few and far between. Since it is our most shade tolerant conifer, hemlock is an excellent species for underplanting. After thinning a hardwood or mixed wood stand, plant hemlock at rates of 12-25 per hectare (5-10 per acre). The high humidity levels and slightly-opened canopy make for excellent growing conditions. It can also be used to speed up the natural succession in old fields, especially those that have poplar mixed in with the white spruce. Plant in small patch cuts with white pine, sugar maple and yellow birch (this is where it may be useful to put rotting wood in the planting hole) or underplant amongst the poplars. As with red spruce, they should not be planted beneath older white spruce as they tend to suffer more insect damage. This species is also well-suited to streamside plantings where there is some existing cover.
Hemlock, like White Pine, at one time was one of the principal species of our native trees but due to fires and cutting, this tree now exists in small isolated areas principally in gullies formed by brooks or rivers. It is one of the largest trees reaching a height of 70 feet or more and a diameter of up to 2 feet. Its best growth is attained mixed with sugar maple and yellow birch, but occurs in pure stands. Around here it is generally mixed with white pine, red and white spruce, balsam fir and various hardwoods. It will grow in the shade of other trees. A very reliable distinguishing feature of this tree is its leaves. Always appearing in two ranks, each is attached by a tiny thread-like stalk to the side of the twig. No other eastern conifer has this stalked leaf. The wood is harder and more coarse-textured than most softwoods. It has a great tendency to split between the annual rings. It is used mainly for general construction and railway ties.
Although we cannot go back in time to see the forests of PEI at the time of settlement by Europeans, we can acquire a reasonable picture by analysis of the written records of that time. This has been achieved by Dr. Doug Sobey in his work “Early Descriptions of the Forests of Prince Edward Island”. Many describers of the time indicate that hemlock was a significant component of the island’s forests occuring either as single-species pure stands or in association with the island’s principal hardwood trees. One particularly interesting description of an area where hemlock was prevalent was along the Pinette River. That is because there still exists today a stand of trees called “Pinette Hemlocks”, that would have been present during the time of its first recording. Many recorders commented on the large size of hemlock, second in size only to white pine. Enormous sizes of up to six feet in circumference were mentioned, but often 2 to 3 feet were the norm. Even back then, hemlock was noted for its nature to crack and split and was restricted to “rough work”. However, it was found to be quite resistant to decay and was espically useful in the structure of wharves, bridges and mill dams. On the other hand, this resistance to rot had a down side. Pioneers who were clearing the forest for farm land noted it took hemlock stumps a very long time to decay, up to 30 years in some cases. Hemlock bark was also used in tanning leather, and the leaves yielded medicinal properties.