HARDINESS: Zones 6 to 9
PREFERRED SOIL pH: Acid
PREFERRED SOIL TYPE: Well-drained, otherwise adaptable
PREFERRED LIGHT: Sun to partial shade
ATTRIBUTES: Glossy leaves, fragrant flowers, conelike fruits; for specimens
SEASON OF INTEREST: Evergreens year-round; deciduous spring to fall
FAVORITES: M. grandiflora, M. virginiana, M. x soulangeana and cultivars
QUIRKS: Shallow roots are easily damaged by tilling
GOOD NEIGHBORS: River birch, hollies, pines
WHERE IT GROWS BEST: Sun to partial shade; large leaves need protection from wind
LONGEVITY: Lives 100 years or more
POTENTIAL PROBLEMS: Splintered limbs and crowns from ice storms
SOURCE: Nursery plants
DIMENSIONS: 15-80 ft (4.6-25 m) tall, to 40 ft (12.2 m) wide
Magnolia in the Landscape
One of the most beloved of all trees, magnolias delight the senses with their glossy foliage, fragrant blossoms, and majestic shape. This is a diverse group of trees, with giant species that reach heights up to 80 ft (25 m) and have leaves up to 2 ft (0.6 m) long, as well as more manageable types that grow 15 ft (4.6 m) high.
Large magnolias are often grown as specimens in the lawn or near the corner of a house. Smaller magnolia trees are lovely planted in groupings along the edge of a driveway or as part of a border. Because the large leaves block so much light and the shallow roots resent disturbance, grass and groundcovers should not be grown beneath magnolias. Besides, most species look best when the lower branches sweep the ground, where the flowers and conelike fruits are clearly visible.
More Cold, Less Space
The famed magnolia of the Southeast is the evergreen southern magnolia (Magnolia grandiflora), which has 8 in (20.3 cm) long leaves and scented, waxy, 10 in (25.4 cm) wide, creamy white blossoms in early summer. The species is hardy to Zone 7, as is 'Little Gem', a columnar variety reaching 30 ft (9.1 m) that is ideal for hedges and smaller gardens. The cultivars 'Edith Bogue', 'Victoria', and '24-Below' will survive in Zone 6.
Even hardier is the sweet bay magnolia (M. virginiana), which will survive in Zone 5 and tolerates shade and wet soil. It is evergreen in warm climates and has round, ivory blossoms. The saucer magnolia (M. x soulangeana), hardy to Zone 4, produces large, cup-shaped flowers in white, pink, or lavender before the leaves appear in spring. It reaches 15 ft (4.6 m) high and equally wide. There are many lovely cultivars, including the rose-flushed 'Alexandrina', purple-stained 'Lennei', and rose-purple 'Burgundy'.
Magnolias thrive in sun to partial shade and slightly acid soil with average to good drainage. In Zones 6 and 7, be careful to avoid planting in low spots, called frost pockets, where cold air settles in winter and can damage flower buds in spring. Also select a protected site where winter winds can't shred the leaves.
Plant magnolias in the spring in Zone 6 or from fall to early spring in Zones 7 to 9. Dig a wide planting hole and settle the tree at the same depth at which it grew in its container or in the field. Fill the hole around it with soil, water thoroughly, and spread a 3 in (7.6 cm) thick mulch of shredded bark on the soil above the root zone to maintain soil moisture in hot weather. Should a drought strike the first summer after the tree is planted, water the tree weekly by slowly dripping water onto the root zone for an hour or longer each time you irrigate.
Magnolias need no pruning and have no serious pest problems, but they can be damaged by winter ice storms. Prune away dead or damaged limbs in late winter and the tree will usually recover after a year or two.