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Tuesday, November 24, 2015




Tuesday, 9:00 AM.  35 degrees F at the ferry dock, 32 on the back porch.  Wind variable, calm  The sky is mostly cloudy, the humidity 70%.  The barometer stands now at 30.30" and is falling, predicting the possibility of rain tomorrow.
   Canadian Hemlock, Tsuga canadensis, in the Pine Family (Pinaceae), is a very large tree that can grow to 75 feet in its natural habitat; ravines and slopes in eastern Canada, around the Lake States and in the mountains south into the Carolinas. It is closely related to the gigantic hemlocks of the western mountains and coastal rain forests.   As Canadian hemlock progresses south in its native range it is increasingly found only in relict populations in deep ravines and north facing slopes of lakes and rivers.
   I have fond memories of iconic "hemlock forests" in New York City, along the banks and bluffs  of the Bronx River in the New York Botanical Garden, and again in the ravines along the Mianus River, along the New York and Connecticut border, the later preserved by the first project of The Nature Conservancy.  Both these forests, or more properly groves, were comprised mostly of huge, mature hemlocks.  Unfortunately, both those populations are under great stress from climate and human activity, and suffer from insect attacks such as that of the wooly adelgid, and no longer reproduce themselves sufficiently to maintain their populations.
   As an individual specimen Canadian hemlock is slow to medium in speed of growth and has a rather graceful shape  in youth, becoming wide-spreading, open and picturesque with great age.  In the landscape, its dark green needles provide a good color contrast with other plants.
  The soft, pointed  needles are two-ranked along the branches, much like those of balsam fir, which they somewhat resemble but are very much smaller, only 1/2 inch long or less.  The upper surface of the needles are dark green, the underside with two whitish bands.  It bears very small cones that shed their seeds during the winter, the cones falling off in the spring.
   Because it takes to shearing well when begun young, it can be kept in control with judicious pruning, and it is most often used as a hedge plant.  It is less successful the further south and west it is planted.  It can be quite expensive because of its slow growth in the nursery and it probably is not used to its full advantage because of cost.
   I like to use them, un-sheared, to provide added diversity to forested areas along Lake Superior, and because of their excellent shade tolerance.

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