Southern magnolia, Magnolia grandiflora, produces large, showy white flowers. The Southern magnolia tree is widely recognized across Southern states, and is the state flower of Mississippi and Louisiana. There are many magnolia varieties that can be grown outside the south and across the United States. Learn how to grow and care for the Southern magnolia.
Growing the Southern Magnolia
The Southern magnolia grows primarily in Zones 7-9, but some varieties will grow in Zone 6 and 10. It is an evergreen tree that will grow 60-80’ high x 30-50’w. Southern magnolia trees have a pyramidal form and a slow to medium growth rate.
This Magnolia variety, a beautiful flowering tree, known for its showy, saucer shaped white flowers and large evergreen leaves. It needs ample room to develop, so it is best used as a specimen tree on large lots, planted well away from structures. The southern magnolia can also be massed or used for screening in parks and on large estates. It has fragrant, waxy creamy-white flowers from late spring to midsummer. They are followed by strawberry-like red fruits. The leaves are a lustrous dark green above, and downy texture on the underside of the leaf.
Protect Southern magnolias from winter aun and winds in the northern parts of the growing region. Plants may have flower buds damaged by late spring freezes, but this won’t kill the tree. This magnificient tree has large surface roots that make ground covers or grass difficult to grow.
The soil should be rich, acid, well-drained and be in full sun to light shade. It thrives in consistently moist soil, but should be able to drain freely and not be overly wet or boggy.
Caring for the Southern Magnolia Tree
Transplant balled-and-burlapped or container-grown magnolia plants in winter or early spring. To help retain soil moisture and acidity, add lots of peat or well-rotte oak leaves to the soil at planting time. The trees may drop their leaves after transplanting but they will recover rather quickly. Maintain a 2-4” layer of organic mulch such as pine needles or shredded pink bark to acidify the soil and improve soil fertility. Young plants will grow faster if given an annual application of acid plant food.
Pruning can be done after flowering only if necessary to shape the tree. Ice and snow damage may cause twigs and small branches to fall and become a minor litter problem.
Propagation is done by layering in spring. Remove the seeds from their covering and sow in fall. Take cuttings in mid-to late summer.
There are no serious pests and diseases, although scales may cause yellowing of leaves. Prune out badly infested branches and spray the remaining stems with horticultural oil in spring.
Magnolia Species for Colder Climates
Cucumber-tree magnolia (M. Acuminata) is hardier, surviving temperatures as low as −25 degrees (protected sites in Zone 4). It is deciduous rather than evergreen. The flowers are not as showy and the fruits resemble small, unripe cucumbers. It grows well in the dappled shade of oak trees.