Few trees conjure up the warm summer nights and unique plant communities of the Deep South like the Southern magnolia (Magnolia grandiflora). This evergreen beauty is right at home in North Carolina but also grows throughout the country in U.S. Department of Agriculture plant hardiness zones 6 to 10, depending on the variety. It is the only magnolia species grown in North Carolina that is reliably evergreen, though the sweet bay magnolia (Magnolia virginiana) is semi-evergreen -- in mild winters it may retain its foliage through the winter, which it does quite reliably in the lowland, coastal parts of the state. Sweet bay magnolia is hardy in USDA zones 5 to 9.
Southern magnolias grow to 80 feet tall in their native habitats, but several dwarf varieties have been bred for gardeners with limited space. "Baby Doll" (Magnolia grandiflora "Baby Doll") grows about 22 feet tall and wide, giving it a more rounded shape than the typical upright or pyramidal form common to most magnolias. "Little Gem" (Magnolia grandiflora "Little Gem") grows in a narrow, pyramidal form from 12 to 20 feet tall and only 10 feet wide. Both have smaller than average leaves and flowers in proportion to their diminutive size.
Varieties With Large Flowers
Magnolias are known for their large, showy flowers, but a few varieties have truly humongous blossoms. "Goliath" (Magnolia grandiflora "Goliath") is a compact specimen with profuse displays of 12-inch flowers, extending unusually late into the summer for a magnolia. "Majestic Beauty" (Magnolia grandiflora Majestic Beauty") has equally large flowers and big, glossy green leaves, growing from 35 to 50 tall with a pyramidal growth habit. "Majestic Beauty" makes a superb specimen tree and is one of the most popular ornamental cultivars in North Carolina.
Magnolias are generally considered slow-growing trees, but there are a couple of varieties that make up for this deficiency with a speedy growth habit. "Russet" (Magnolia grandiflora "Russet") grows quickly to 50 feet in a dense columnar shape. The trees have smaller dark green leaves with a fine, orange-brown fuzz on the underside. "Samuel Sommer" (Magnolia grandiflora "Samuel Sommer") grows to 40 feet tall with thick, leathery 8-inch leaves.
Magnolias grow naturally in the Piedmont and Coastal Plain regions of North Carolina, but varieties selected for cold hardiness allow them to be grown in the colder mountain regions, as well. Most evergreen magnolias are hardy only to USDA zone 7, though "Edith Bogue" (Magnolia grandiflora "Edith Bogue") and "Victoria" (Magnolia grandiflora "Victoria") can both be grown in USDA zone 6, which covers most of the western North Carolina mountains. "Edith Bogue" grows quickly to 35 feet and is known for having branches that resist breakage in snowy conditions.
Sweet Bay Magnolia
The sweet bay magnolia is also known as swamp magnolia because of its affinity for growing in wet places. It can grow into a single-trunked tree up to 60 feet tall, but it is more often seen as a multitrunked specimen under 30 feet in height. Superficially, it closely resembles the Southern magnolia, but the leaves are not as thick and leathery and the flowers are smaller, usually 2 to 3 inches across. It grows in part shade or full sun and is a superb ornamental native for wet places in the landscape.
- N.C. State University Extension: Southern Magnolia
- Missouri Botanical Garden: Magnolia Grandiflora "Edith Bogue"
- Cal Poly Urban Forest Ecosystems Institute: Victoria Magnolia
- Clemson Cooperative Extension: Magnolia
- University of Florida IFAS Extension: Southern Magnolia
- NC State University Extension: Sweet Bay Magnolia
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