Trees and Shrubs of the Eloise Butler Wildflower Garden

Notes: Eastern Hemlock is not indigenous to the Garden. Eloise Butler planted the first ones in Sept. 1911 - plants obtained from the Park Board Nursery, and again on May 28, 1914. On that date she recorded planting 28 Hemlocks and these are probably the oldest southern most remaining stand in the state and this stand near the back gate contains the largest known Eastern Hemlock in Minneapolis which is now on the Minneapolis Heritage Tree List for its "champion size". This tree is 80 feet high with a circumference of 84 inches. A second tree on the east path between Guidebook stations 16 and 17 is on that list for its "significant" size", it being 80 feet high and 69 inches in circumference.

Tsuga canadensis is the only species of Tsuga found in Minnesota. Gardener Cary George planted 15 new 2-foot trees in 1989. Eastern Hemlock is found in North America in the eastern 1/3, from Ontario and Minnesota eastward to the coast and into the southern states except for Florida.

Eloise Butler wrote this in 1914 about her planting of the Hemlocks: "Hemlock has not been listed among Minnesotan plants; but it has sneaked in, contrary to rule, with the idea that it may sometime break across the Wisconsin border. In order that the face of nature may be changed as little as possible in our trained wilderness, only a few specimens each of the state flora not indigenous to the Garden are admitted."

Endangered: Minnesota is at the far western edge of the range with a native population only known from Pine county. There were previous populations in Carlton and St. Louis Counties but those were mostly logged off and most of the remaining trees succumbed to forest fires and the rest died off. The MN DNR states there are only about 50 mature trees remaining in the wild. Only recently has the tree been listed as of "Special Concern" and in August 2013 was advanced to "Endangered" status. The population in the Garden and the younger population at the MN Landscape Arboretum is therefore of special importance. There are a few other landscape specimens known - one large tree on private land in Washington County for example. The National Champion Eastern Hemlock is in Macon NC measuring 159 feet high, 45 foot crown spread, 192 inches in circumference and scoring 382 points.

Uses: The wood of Eastern Hemlock is brittle and full of knots, thus not valuable for anything but rough wood needs. An extract of Hemlock bark was once a commercial source of tannin for the production of leather and that use led to the destruction of many mature stands of the tree. Other than the bark, the remainder was discarded. Tea was said to be made from the leafy twigs.

In his important 3-volume work, The North American Sylva of 1817-19, Francois Michaux adds considerable detail to the above: "Unhappily the properties of its wood are such as to give this species only a secondary importance, notwithstanding its abundant diffusion; it is the least valuable in this respect of all the large resinous trees of North America. But the regret which we should experience to see it occupying so extensively the place of more useful species is forbidden by a property of its bark inestimable to the country where it grows, that of being applicable in tanning.

It is taken from the tree in the month of June, and half the epidermis is shaved off with a plane before it is thrown into the mill. From the District of Maine it is exported to Boston, Providence, etc., and is almost exclusively employed in the tan-yards. Its deep red colour is imparted to the leather, and I have been informed by tanners that it is inferior to Oak bark, but that the two species united are better than either of them alone."(Ref. #26d)