Hemlock (Tsuga) trees, like many types of conifer trees, grow to an impressive size in favorable conditions. These trees often grow as large as 70 feet in height and 30 feet in width. Various types of hemlocks flourish in across the United States. They grow in abundance in many established forests, providing shade and shelter to understory plants and shrubs. Many forests harbor hemlock specimens over 200 years old. These long-lived trees provide interesting specimens in parks, yards and landscapes.
Plant your hemlock trees in the autumn. Select an area that provides full sunlight to partial shade. Prepare the soil for your new hemlock trees before the expected delivery date. Hemlocks thrive in loamy, well-drained soils. Like many other conifer trees, hemlocks prefer a slightly acidic soil. Add some organic mulch, such as shredded pine bark, to increase the soil porosity and help lower the pH level. Avoid adding soil amendments to existing soil that already contains plenty of organic materials and provides a loose, rich composition for planting.
Dig holes for your hemlock trees. Make the holes deep enough to place the surface of the hemlocks' rootballs even with the adjacent surface. Dig holes about twice as wide as the width of the rootballs. Carefully remove the rootballs from their burlap wraps or containers. Use pruning shears to cut off any roots that form circles around the rootballs. Place the rootballs in the prepared holes and back-fill with soil. Tamp down the area around the small trunks to provide a level surface. Fill in any deep depressions with a little additional soil. Thoroughly soak the soil around your newly planted hemlocks.
Spread some mulch over the soil covering the roots. Apply 2 inches of pine bark mulch around your new hemlock trees. Do not place the mulch near the trunks of your trees. Apply water at infrequent intervals to encourage healthy roots. Allow the surface soil to dry a little between watering sessions, but keep the soil slightly moist near the roots.
Maintain your hemlock trees by pruning away any broken and dead branches. These trees may require occasional shaping to shorten overgrown branches. Do not heavily prune--excessive pruning may damage your trees and create uneven growth. Encourage attractive branches by keeping your pruning to a minimum.