Tsuga canadensis/Canadian Hemlock

Canadian hemlock, Tsuga canadensis

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?

Canadian hemlock, Tsuga canadensis 'Prostrate'

Tsuga chinensis/Chinese Hemlocks

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.

Location Matters

I grow Canadian hemlocks in the Washington, D.C. area, Zone 7A. If you've grown it and have comments you'd like to see included here, send 'em along, and tell me where you garden.

More Great Info in Print

Gardening with Conifers by Adrian and Richard Bloom

Conifers for Gardens, an Illustrated Encyclopedia by Richard Bitner
Growing Conifers by the Brooklyn Botanic Garden
Native and Cultivated Conifers for NE North America by Cope and King
Dirr's Hardy Trees and Shrubs by the best-known authority on the subject.

Photo credits: Top, University of Vermont. Middle, by Brooklyn Botanic Garden. Botton by Jeffrey Gustafson at Wikimedia.com, taken at Brooklyn Botanic Garden.