Eastern Hemlock
Scientific name: Tsuga canadensis
Hemlock groves are found only in the Three Lakes region of Lewisboro where they cover almost 500 acres along the south shores of Lake Waccabuc and Lake Oscaleta. Eastern hemlocks, along with red cedar, are our only native evergreen trees. These are one of the most important tree species in northeastern forests. Because they are shade tolerant they can grow in riparian (along streams) areas where they keep the temperatures cool for trout and other fish in the heat of the summer. They also prevent erosion. The BAD NEWS is that our hemlocks are suffering from wooly adelgid infection, caused by a non-native aphid that first appeared in CT in 1992. It is predicted that this pest will overwhelm the majority of Eastern hemlocks, threatening this keystone species with extinction. Many are dead. No hemlocks have shown resistance to this insect.
Leaves
Evergreen flat single needles
Fruit
Brown cone in fall about 3/4 of an inch in size which matures in early fall.
Flowers
Pollen is shed in March and April. The flowers themselves are inconspicuous.
Habitat
Learn about this important habitat here.
Leaves
Evergreen flat single needles
Bark
Initially grey brown and smooth but they turn to a red-brown with wide furrows and ridges.
Fruit
Brown cone in fall about 3/4 of an inch in size which matures in early fall.
Flowers
Pollen is shed in March and April. The flowers themselves are inconspicuous.
Ecosystem Connections
These trees help to prevent erosion on stream banks and keep the water cool in summer so that trout and other amphibians can flourish.
They also provide thermal protection to wildlife in winter, when other trees have lost their leaves.
Their seed cones provide food to up to 90 different species of birds!
How You Can Help
If you have a hemlock on your property, you can protect it by applying a dormant oil spray.
Wow
Naturalist Ken Soltesz has estimated that some of the hemlock in the Three Lakes are are up to 600 years old!
Close Up
Infected with Wooly Adelgid
Range Map
Tree
More on Trees and Shrubs in Lewisboro
Lewisboro was once entirely forested except for patches of open field caused by fire and wetlands and ponds which were expanded by beaver dams. Although it is hard to believe, by 1800 most of Lewisboro’s forests had been cut down and replaced by farms. In 1820 so many trees had been cleared that there was no shade anywhere along the route from Boston to New York.[1] But by the mid-1800’s farming here became uneconomical and as farms were abandoned, the forests began to re-grow. Today, 70% of New York is once again forest, what some call ‘the great environmental story of the United States’[2]. These new forests provide us with beauty and recreation, clean air and water, flood control, erosion prevention, carbon sequestration, cooler temperatures and habitat for other plants, insects, birds and other wildlife.
[1] Cronon, William. Changes in the Land. Macmillan, 1983.
[2] An Explosion of Green. B. Mckibben. Atlantic Monthly 275 (April 1995): 61-83.