Southern Magnolia (Magnolia grandiflora): History, Cultivars, Growth Rate & Care

Magnolia grandiflora, commonly known as the southern magnolia or bull bay, is a tree of the family Magnoliaceae. The tree is found on the edges of bodies of water and swamps, in association with sweetgum (Liquidambar styraciflua), water oak (Quercus nigra), and black tupelo (Nyssa sylvatica). In more sheltered habitats, it grows into a large tree, but can be a low shrub when found on coastal dunes.

Fossil records show that the genus Magnolia has existed for over 36 million years, with some estimates placing it as far back as 58 million years ago. The magnolia family is one of the oldest flowering plant families on Earth, and its presence can be traced to various regions across the globe.

The Southern Magnolia tree, in particular, is native to the southeastern United States from Virginia to central Florida, and west to East Texas. The tree was first discovered by Europeans in 1688 and was later named after Pierre Magnol, a French botanist. The tree’s hardiness and adaptability to the Southern climate made it a popular choice for cultivation, and it has since become a symbol of the region.

The Southern Magnolia tree has also been cultivated in Asia, Europe and the Americas for centuries. The tree’s beautiful flowers and its ability to withstand hurricanes and fires have made it a beloved species for both its aesthetic and practical qualities.

The oldest Southern Magnolia standing today is on Washington State Park in Washington, Arkansas. The tree is said to have been planted near an important road junction in 1839 by Gen. Grandison D. Royston. It was near a blacksmith shop where Jim Bowie fashioned his famous knife.

Southern magnolias, in particular, are known for their leaf and fruit litter, which make for a less manicured appearance and and an increased requirement for clean-up. Their reputation as messy trees is promoted by their loss of leaves throughout the year.

Known as an aesthetically charming unofficial representative of the southern United States, the Southern magnolia is also an official representative of Mississippi. In 1900, students from Mississippi voted the Southern magnolia in as the state flower, a decision that was formally passed by legislature in 1952. In 1938, schoolchildren again voted for the Southern magnolia, this time as their state tree, and legislation was passed making it the official state tree of Mississippi. The tree has also been used in various cultural and religious practices, with its flowers often being associated with purity and dignity.

Characteristics of Southern Magnolia

  • The only evergreen in the Magnoliaceae (magnolia) family
  • Southern magnolias can grow quite large, reaching heights of 60 to 80 feet tall with a spread of 30 to 40 feet. In ideal conditions, they may grow even larger.
  • Possesses leathery evergreen ovate to elliptic leaves (5 to 10 inches long) that are glossy dark green above and variable pale green to gray-brown beneath
  • Can be grown in USDA Zones 7 to 9 and in Zone 6 if sited in a protected location.
  • The tree produces large, fragrant, creamy-white flowers that can reach up to 12 inches in diameter. These flowers bloom in late spring to early summer.
  • Produces large, spherical cone-like fruiting clusters (3 to 5 inches long) that mature in late summer to early fall.
  • Southern magnolias can be propagated from seeds, cuttings, or grafting. However, they are slow-growing trees, and it may take several years for them to reach a desirable size.
  • When the tree is young, the bark is smooth and silvery-gray, but as it matures, it develops a more rugged, furrowed appearance.
  • Has a high tolerance for salt.
  • Has a shallow and wide-spreading root system.
  • The branches are covered with a smooth, gray bark that is relatively thin. The tree’s branches tend to grow in a somewhat horizontal fashion
  • The lifespan is generally long, with the tree reaching maturity after many years.
  • Southern magnolia grows at a moderate rate, typically adding 12 to 24 inches (31-61 cm) per year.
  • It is a symbol of the American South and is the state flower of both Mississippi and Louisiana. It is often associated with hospitality and grace.
  • Several cultivars have been developed to preserve the tree’s ornamental features while giving it a more manageable size. 

Cultivars of Southern magnolia (Magnolia grandiflora)

Cultivar NameCharacteristics
Edith BogueHardy, early bloomer, compact form
Bracken’s Brown BeautyDark brown leaf undersides, considered one of the best selections
Little GemDwarf, upright form, slow-growing, early flowering
Majestic BeautyLarge, dark green leaves, pyramidal shape, and profuse flowering
Samuel SommerUpright, rapid growth habit, large flowers
VictoriaVery hardy, small flowers, rust-red leaf undersides
Charles DickensBroad leaves, large flowers, large red fruit
GoliathLarge flowers, long blooming period, bushy habit of growth
HasseDense, compact form, suitable for hedges or screens
Glen St. MaryCompact form, early bloomer, slow-growing, bronze leaf undersides
GloriaLarge flowers, large leaves
CairoEarly and long flowering period
Praecox FastigiataUpright, narrow growth habit

How to grow and care for Southern magnolia (Magnolia grandiflora)

  • Location: Choose a location with full sun to partial shade, and well-draining soil. Southern magnolias can grow in a variety of soil types, including clay, loam, and sand, but they prefer acidic soil with a pH between 5.0 and 6.5.
  • Planting: Dig a hole twice as wide and just as deep as the root ball of your tree. Place the tree in the hole, ensuring the top of the root ball is level with the surrounding soil. Fill the hole with soil and gently tamp it down to remove air pockets. Water the tree thoroughly after planting.
  • Watering: Water your Southern magnolia regularly during the first year to help it establish a strong root system. Once established, the tree is relatively drought-tolerant but will benefit from occasional deep watering during prolonged dry periods.
  • Mulching: Apply a layer of mulch around the base of the tree, extending at least 3 feet from the trunk. This will help retain moisture, regulate soil temperature, and suppress weed growth. Be sure to leave a small gap between the mulch and the trunk to prevent rot.
  • Fertilizing: These magnolias generally don’t require much fertilizer, but you can apply a slow-release, balanced fertilizer in early spring if your tree appears to be growing slowly or has pale leaves.
  • Pruning: Prune your magnolia in late winter or early spring to remove dead, diseased, or crossing branches. You can also shape the tree to your desired form, but be cautious not to remove too much foliage, as this can reduce flowering.
  • Pests and Diseases: These magnolias are relatively resistant to pests and diseases, but they can occasionally be affected by scale insects, aphids, and leaf spot. Monitor your tree for signs of infestation or disease and treat it promptly with appropriate measures.