Tsuga canadensis / Canadian Hemlock

I couldn’t resist this stately conifer of the East — at $15 each — and have five in my garden. One of a very small group of conifers that tolerate shade, it’s also threatened by a virulent Asian insect that I’m happy to report can be dealt with successfully by the watchful gardener.

Here’s an article I wrote about the destruction of hemlocks in the wild caused by the wooly adelgid insect (next photo). It includes two remedies for protecting hemlocks, both do-able by the home gardener.

Native from Georgia to New Brunswick and west to Wisconsin.

Details

  • In the wild they grow to 40-70 feet tall. In urban situations they often stop growing at 25 feet tall by 10 feet wide.
  • Abundant dwarf forms are available, the most popular of which is the weeping variety ‘Pendula’ (bottom photo).
  • Tolerates full sun to full shade, though it does best in partial sun/shade.
  • Hardy to Zone 3.
  • Sources say that deer eat hemlocks, but mine haven’t suffered even a nibble in my deer-infested backyard.

Care

  • Average drought tolerance after first year or so on site.
  • Avoid roadsides (salt spray) and exposed sites (unbroken wind).
  • Stake new hemlocks for 2-3 years.
  • Can be sheared to form a hedge, according to all the sources, but that would sure spoil its gorgeous shape and form.
  • Sources warn to be careful if transplanting in the fall and recommend watering well and mulching, but you’d do that anyway, right?

Tsuga chinensis/Chinese Hemlocks

wooly adelgid

Now you may be inclined against this plant, since the hemlock-killing wooly adelgid came to the U.S. on board one of them (in fact, to a large conifer collection in Virginia). But if growing native hemlocks isn’t an option where you live (too infested with adelgids or too hot), consider growing the adelgid-resistant Chinese hemlock. It’s more expensive but does very well in hot, humid climates. Hardy only to Zone 6.