American Hornbeam Plant Profile

American hornbeam leaves

 

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The American hornbeam grows natively in eastern North American and can be found from Maine to Minnesota and as far south as Texas and Florida. This deciduous hardwood shade tree prefers moist, acidic soil and produces dark green summer leaves that turn a variegated orange in the fall. Come winter, its blue-gray bark creates a beautiful contrast to the snow in northern climates. The hornbeam is a great tree to add to any backyard landscape since it's medium in size and is resistant to pests and diseases.

The American hornbeam's botanical name is Carpinus caroliniana. It is part of the Betulaceae (or birch) family and has several nicknames, including blue beech, muscle beech, water beech, muscletree, musclewood, and ironwood. The reference to muscle relates to the tree's characteristic fluted trunk and branches that look like muscle tissue. Its wood is very strong and hard and sometimes is used to make wooden tools and other implements.

Scientific Name Carpinus caroliniana
Common Name Blue beech, musclewood, ironwood, water beech
Plant Type Deciduous tree
Mature Size 20 to 25 feet wide and 20 to 35 feet tall
Sun Exposure Full shade to full sun
Soil Type Moist, well-drained
Soil pH 4 to 7.4
Hardiness Zones 3 to 9
Native Area North America

How to Grow American Hornbeam

American hornbeam is suitable for gardeners in USDA Plant Hardiness Zones 3 through 9 and can adapt to a wide variety of light conditions. For best results, start American hornbeam from seed on site, or select a young tree from a reputable nursery. Plant it in the fall, as the seedlings need light shade to propagate.

This species is highly adaptable and can withstand some flooding, but it has a hard time dealing with drought conditions. Other than providing regular watering, this tree is relatively low-maintenance. However, it can be difficult to transplant due to its expansive root system.

Light

American hornbeam is commonly found within the understory of hardwood forests, so it can thrive in full shade. It is also quite adaptable and can tolerate full sun.

Soil

Hornbeams prefer moist or wet soil that is acidic, although they can tolerate slight alkalinity. Loam soil is best, but clay soil is okay, too.

Water

This tree needs regular watering during the dry season. Installing drip irrigation for summer maintenance works great. When the weather is hot and dry, give the tree a deep soak once each week. To establish the roots of a new tree, keep the ground damp for the first two or three years, during the growing season.

Temperature and Humidity

Hornbeams grow in a wide range of climates, from Canada to Florida, so they are tolerant of broad temperature differences and seasonal conditions. However, the species is less common in the dry states of the western U.S.

Fertilizer

American hornbeams typically do not need fertilizer, especially when the ground around the tree has grass that is fertilized.

Landscape Uses

American hornbeam looks gorgeous in all seasons. And while it's a slow grower (it can take decades to reach its maximum size), this tree could cause crowding problems for neighboring trees down the road. Pair it with medium-size evergreens, making sure to leave ample growing space for each species. You can also use an American hornbeam tree as the focal point in a perennial garden by surrounding it with complementing flowers and mulch. That way, it won't outcompete other trees.

American hornbeam grows naturally in the understory of forests, making it a medium-sized variety suitable to residential landscapes. This species will top out at about 20 to 35 feet tall. The leaves of the hornbeam are medium in size (2 to 5 inches long), are blue-green in color, and elliptical in shape. In the fall, this tree rewards growers with a display of leaves that varies from yellow to orange and purple to red.

The hornbeam produces a nutlet surrounded by a bract. Over the course of the season, several nutlets and bracts become stacked, creating a fruit cluster that dangles off the limbs.

Pruning

If you'd like your hornbeam tree to have a single trunk with foliage growing above, make sure to prune it to have only one central leader. This type of tree can form multiple trunks if left to its own devices. You can also prune this species to create a formal hedge or living fence. This works well for town residents wanting privacy without the eyesore of a head-high fence. Regular shearing will be necessary to maintain the shape.

Common Pests and Diseases

American hornbeam is extremely tolerant of both pests and disease, so problems rarely arise. However, hornbeam trees can develop cankers and can present with leaf scorch or leaf spots. Proper maintenance and appropriate water amounts should prevent this. Hornbeams rarely suffer from insect infestation, but when they do, maple mealybugs and two-lined chestnut borers are usually the culprits.