They grow up to 70 feet tall and appear pyramidal or conical.
Their tiny,fragranttwo-toned green needles give them a fine texture.
Their needles are linear but form a spiral.
The Spruce / Adrienne Legault
Crushing the needles releases their aroma.
They make small oval-shaped seed-containing cones just under an inch long, hanging from twig tips.
Plant Canadian hemlock in the early spring.
The Spruce / Adrienne Legault
These trees grow slowly or moderately, averaging about 12 to 24 inches annually.
Canadian hemlock trees are a good, stately tree that is shade-tolerant and makes very little mess.
It keeps its graceful look throughout the seasons.
The Spruce / Adrienne Legault
However, you’ve got the option to keep Canadian hemlocks small by pruning them regularly every year.
It is best grown in cool, moist, well-drained soils and protected from the wind.
Plant the trees 30 to 40 feet apart.
The Spruce / Adrienne Legault
Their sunlight requirements provide flexibility in a cold climate (USDA zones 3 to 5).
Soil Needs
These trees require soil that is moist but has good drainage.
They prefer a loamy,acidic soil.
The Spruce / Adrienne Legault
Water Requirements
Hemlock trees require a fair amount of water.
This tree does not tolerate standing wet soil nor prolonged periods of drought.
The best method of watering is slow watering once a week.
Start the watering process with a general spray of the trunk and leaves.
This will help to wash away insects and pollution residues.
Ideal Temperature and Humidity
This tree grows in regions with cool, humid climates.
In the northern areas, January temperatures average 10 degrees Fahrenheit, and July temperatures average 60 degrees Fahrenheit.
Precipitation ranges from less than 30 inches.
Fertilizer Requirements
This tree needs a well-balanced fertilizer (10-10-10) about once a year.
For the amount to use, follow product label instructions.
Wait a few months until the tree is established.
Pruning
Canadian hemlock trees do not need much pruning unless limbs are damaged by weather or disease.
Prune in spring and early summer because the tree has active growth and will easily recover.
Compact cultivars, essentially shrubs, are commonly used as privacy hedge plants or in foundation plantings.
If you begin pruning them when young, they are fairly easy to shape.
Propagating Canadian Hemlock
Canadian hemlock cuttings can be taken from semi-hardwood branches for propagation in late summer.
Even dwarf varieties are not suitable for growing in containers, except when grown as abonsai.
Infested trees have white woolly masses at the base of the needles on the undersides of the twigs.
Treatment with pesticides is available, but controlling an infestation is extremely difficult.
Canadian Hemlocks can also be damaged or destroyed by browsing deer.
If you have a heavy deer population, choose analternative treeorshrubwith better deer resistance instead.
The toxic hemlocks areConium maculatumandCircuta maculata.They are not related to the non-toxic Canadian or eastern hemlock tree.
The pest kills some trees within a few years, while others seem resistant and survive the attacks.
A hybrid hemlock that is not vulnerable to the pest has been developed.
Canadian hemlock is a long-lived tree.
Most long-lived species are slower growers.
Canadian hemlock can grow up to 2 feet a year in the best conditions.
For reference, fast-growing trees can grow up to 5 feet per year.
O. Canham, Hugh.Hemlock and Hide: The Tanbark Industry in Old New York.Northern Woodlands, 2011.
University of Kentucky College of Agriculture, Food, and Environment.
U.S. Forest Service Southern Research Station.
North Carolina State Extension.
North Carolina State Extension.
When Can I Prune My Hemlock Trees?New York Botanical Garden.
New Hemlock Hybrid Withstands Killing Insect.
U.S. Department of Agriculture, Agricultural Research Service.
