The Best Soil Conditions for Hemlock Trees

Hemlocks (Tsuga canadensis) are among North America's most gracefully cone-bearing trees. Becoming magnificent landscape specimens or nice in a row as a hedge or screen, their growth and beauty depends on their growing conditions, particularly soil. The best soil for hemlock is an organic-rich loam that is acidic and is consistently moist. The soil should drain well, never becoming soggy or flooded.

Soil and Composition

In its native habitats, the hemlock grows on loams and sands that may have layers of fertile silt or incorporated gravel. Organic matter, such as decaying conifer needles, is a key component to making optimal growing conditions. Heavy clay soil must be made more porous with the use of mulch and compost. Soil should not be hard and compacted.

pH Range

Hemlock grows in highly acidic to near-neutral pH soil, corresponding to pH readings of 4.0 (highly acidic) to 7.2 (near neutral). Alkaline soils, those above a pH of 7.2 are not ideal because they will inhibit intake of vital nutrients.

Moisture and Drainage

Soil must range from barely dry to very wet, but always have good drainage. The finest plant growth occurs on consistently moist soils that never flood or are soggy throughout the year. Water should soak fully into the soil within 5 to 10 minutes after a rainfall. Slightly drier soils are only good in climates that are cool in summer.

Types Of Hemlock Trees

Called the aristocrats of evergreens, hemlock trees (Tsuga spp.) are striking, graceful, even poetic. Keep in mind that they can take a long time to grow to their full height though, so if you're looking to add some hemlocks in their full glory to your yard, then buying already grown varieties is a better option for you. The elegant hemlock species loves cool, moist slopes, well-draining soil and partial shade in U.S. Department of Agriculture plant hardiness zones 3 through 7. Weeping cultivars include Sargent's weeping hemlock (Tsuga canadensis "Pendula"), which grows to 15 feet tall and twice as wide, its weeping branchlets cascading over straighter branches in USDA zones 4 through 8. It grows into an enormous and glorious tree, sometimes shooting up more than 250 feet tall with a branch spread of 40 feet. The tree does best in USDA zones 6 through 8. Its mahogany-hued bark develops attractive fissures as the tree matures, giving it a uniquely rugid look.