Sweetbay Magnolia

• By Pat Chadwick
• /
• November 2015-Vol.1 No.11
• /
• 15 Comments

by Pat Chadwick

With all the attention given to global warming these days, most gardeners seek out drought-tolerant plantings for their gardens and that’s a good thing. For the gardener who has wet or poor-draining soil, finding plants that don’t mind soggy feet may be a challenge. Sweetbay magnolia is one plant that comes to mind for such demanding growing conditions.

BACKGROUND

Sweetbay magnolia is a smaller, less majestic cousin of Magnolia grandiflora (Southern magnolia), that beloved aristocratic icon of the southern United States. One of 125 deciduous and evergreen members of the ancient Magnoliaceae genus, sweetbay magnolia was introduced into cultivation in the late 1600s and first appeared in European gardens in 1688.  Its common name, sweetbay, comes from the sweet-smelling bay-like foliage, while the term magnolia honors French botanist Pierre Magnol (1638-1715). Other names for this plant include swamp magnolia and laurel magnolia.

Sweetbay magnolias are native to the southeastern United States where they are found growing in acidic, medium to wet soils, in full sun to part shade. Their range extends north along the Atlantic coast to New York. In the more northern (USDA Zone 5) part of their range, they tend to appear as open, multi-stemmed shrubs or as small 10- to 20-foot trees. In the deep southern part of their range (USDA Zone 9), they are more likely to maintain a tree-like habit and can grow to 60 feet or more. In Virginia, they are most commonly found growing wild in coastal plain areas and are less frequently found in the Piedmont. Although not native to Albemarle County, sweetbay magnolias have reportedly been found growing wild on a single mountain site in nearby Augusta County.  In this area, they typically grow 20 to 30 feet or more tall with a similar spread.

DESCRIPTION

• Habit: Sweetbay magnolias are columnar or vase-shaped. They typically grow as multi-stemmed specimens but can be found with single trunks.
• Foliage: The glossy evergreen to semi-evergreen leaves measure three to five inches in length and are dark green on top with a silvery-looking underside. A breeze can make the tree shimmer as the silvery undersides are exposed to the sun. In this area of Virginia, the evergreen nature of its foliage depends upon the severity of our winter weather. While the tree may lose some of its foliage, it recovers nicely in spring.
• Blossoms: The tree typically blooms in May through June and may occasionally send out random blossoms during the summer months. Because it blooms later in the spring, it is a good alternative to earlier blooming star and saucer magnolias, which are subject to damaging spring frosts. The creamy white flowers are similar to those of the Southern magnolia but much smaller, measuring approximately two to three inches in width. The blossoms are cup shaped and have 9 to 12 petals. Each blossom opens in the morning, closes at night, and lasts for two or three days. Although sweetbay magnolias will thrive in partial shade, they prefer a minimum of four hours of direct sun per day in order to produce their best flowers.
• Fruit: The blossoms are followed in late summer by dark red aggregate fruits, appearing as cones measuring about two inches long. These cones eventually split open to expose flattened, glossy, bright orange-red seeds.

Sweetbay Magnolia Seedpods

• Bark: The bark is smooth and green on young branches and ages to a silvery gray, adding interest to the winter landscape.
• Cultivars: In addition to the native species, a number of cultivars are available commercially.  ‘Henry Hicks’ and ‘Moonglow’ are reported to be more reliably evergreen than the species. Cultivar ‘Santa Rosa’ has larger leaves than the species.

GARDEN USES AND BENEFITS

Their preference for moist, rich, organic soils and their ability to tolerate wet, boggy conditions make sweetbay magnolias a good choice for planting near ponds, along streams, in swampy areas, or in low spots that collect water. Because they can tolerate periodic flooding, they thrive in rain gardens. Sweetbay magnolias make excellent specimen trees in the lawn, as part of a foundation planting, or at the edge of a woodland setting. The tree’s multi-stemmed shrubby form works well in a mixed shrub border.  Its smallish size also makes it a good candidate for planting near a patio where it can help filter light or provide a privacy screen. Used in groupings, these trees may help to define areas, such as playgrounds or parking lots, or to hide an unsightly view. Recognized as being resistant to wind damage, sweetbay magnolia is a good choice for use as a wind break.

Despite its preference for moist soil, sweetbay magnolia is drought tolerant once established.  Proof of this lies in the  accompanying photo of a thriving specimen growing in a dry site south of Charlottesville. With this past summer’s drought conditions during July and August, it weathered the lack of moisture well and exhibited only mild signs of stress.

Sweetbay Magnolia Specimen South of Charlottesville

In late summer and early fall, the clusters of red fruit attract squirrels, small rodents, turkey and quail. The fruit is also popular with songbirds such as blue jays, Northern flickers, towhees, and vireos. The blossoms attract a number of butterflies and moths, including the Eastern Tiger and Zebra Swallowtail butterflies.

CULTIVATION

• Propagation – Sweetbay magnolia may be easily rooted from softwood cuttings.

• Planting — For best results, plant the sweetbay magnolia in the spring in full or partial shade. It prefers evenly moist, acidic soil, but it will tolerate average garden soil provided the pH is 5.5 to 6.5. This tree grows at a medium to fast rate.

• Pruning– Prune after the plant finishes blooming during the growing season. The plant wants to grow naturally with several trunks, but it can be trained to grow with a single trunk. It needs little pruning to develop a strong structure. Prune any diseased, broken, or dead branches all the way to their base. Thin out crowded branches to allow sunlight and air filtration to the inner limbs.

PROBLEMS

Sweetbay magnolias do not have any serious insect or disease problems. Leaf spots may occasionally appear on the foliage but treatment is not normally necessary. Virginia Cooperative Extension (VCE) Publication 450-237 includes this plant among the problem-free trees that are recommended for Virginia landscapes.

This plant often appears on lists of plants that deer seldom browse. However, no plant is ever completely deer proof. So, if you have a deer problem, be aware that they may nibble sweet magnolia leaves and smaller twigs.

SUMMARY

Sweetbay magnolia is a small, gracefully shaped tree that has a lot to offer throughout the year. This native ornamental bears attractive, lemon-scented flowers in spring and sporadically through the summer. Glossy green foliage persists on the tree nearly all year long. Showy red cone-like fruit provides color, interest, and food for wildlife in fall, and smooth gray bark adds beautiful color and contrast in winter.

SOURCES

American Horticulture Society, A-Z Encyclopedia of Garden Plants (2008)

Dirr, Michael, Dirr’s Encyclopedia of Trees and Shrubs (2011)

Mellichamp, Larry, Native Plants of the Southeast (2014)

VCE Pub. 430-026, Trees for Problem Landscape Sites — Wet and Dry Sites, http://www.pubs.ext.vt.edu/430/430-026/430-026_pdf.pdf

VCE Pub. 450 -237, Problem-Free Trees for Virginia Landscapes, http://www.pubs.ext.vt.edu/450/450-237/PPWS-47-pdf.pdf

Weakley, Alan S.; Ludwig, J. Christopher; and Townsend, John E., Flora of Virginia (2012)