This genus is usually known more commonly as the hemlock and has produced some very worthwhile garden forms which are not generally known to gardeners in the United Kingdom. This applies particularly to Tsuga canadensis and its varieties which are very popular in the United States and likely in time to become so in Europe. The foliage is generally similar to the yews but with much thinnerand branches of a more arching habit. They are tolerant of most soil conditions succeeding particularly well in soils that are both moist and well drained.
T. canadensis, the eastern hemlock, originates from the eastern United States and makes a large tree of pyramidal outline not really suitable for any but the largest gardens, if left to its own devices. But it can be trained for Bonsai anddisplays and does well in . It makes a tall graceful tree usually forked near the base, growing 12 to 15 ft. in ten years and ultimately between 75 to 100 ft. This species and its varieties tolerate alkaline soil and in fact seem to prefer them to very acid conditions. There are several dwarf forms which will probably only be available from specialist nurseries at present.
Bennett makes an attractive flat-topped bush with graceful drooping branchlets. This and a very similar semi-prostrate variety Jeddeloh are distinct in offering new forms and texture to the choice of conifers available to the gardener. Both have the mid to light green foliage typical of the species. Both have similar rates of growth making plants of 12 to 18 in. high by a width of 3 to 4 ft. in ten years and eventually a height of 3 to 4 ft. and a width of up to 10 ft.
Cole is an extremely prostrate form which closely hugs the ground spreading slowly to a diameter of perhaps 2 to 3 ft. in ten years and ultimately up to loft, or so. Probably the most familiar variety in Great Britain is pendula which makes a spreading bush, slowly building up in height but always with a very pendulous branching habit. Although slow it will eventually make a large plant as high as 6 to 8 ft. and as broad as 20 ft. although at the ten-year stage perhaps only 18 to 24 in. and 21- to 3 ft. across. It is particularly effective if placed on a bank or a wall where the branches can cascade down the slope or over the edge as the case may be.