The Poison Hemlock was taken from a completely different plant, a member of the Parsley family. It has soft, bluish-green leaves and its cones are usually 1 to 2 inches long. It is found from Alaska to California. T. heterophylla, the Western American Hemlock grows up to 220 feet high. It is pyramidal in growth and the almost horizontal branches divide into many fine branchlets, covered with small, dark green leaves.
Hemlocks prefer cool, moist places.
It is often found along streams and the edges of bogs and swamps, or on steep northward facing slopes. These trees will tolerate partial shade. Not much pruning is necessary for these trees unless you want the lower part of the trunk is to be clear. If this is desired, do not remove too many of the lower branches all at once, instead take only a few branches each year until the desired height of clean trunk is attained. When desired for hedge plants, young Hemlocks, no larger than 1 to 3 feet high, should be used.