Tree Profiles: Saucer Magnolia (Magnolia x soulangiana), Part 1
This is the first half of a two part series on flowering dogwood. The following examines the tree’s distribution and habitat, developmental traits, longevity, height, bark, leaves, flowers, fruit, seed production, root development, and ideal soil conditions.
Saucer magnolia (Magnolia x soulangiana) is a deciduous hybrid magnolia. It is derived from Yulan magnolia (Magnolia denudata) and lily magnolia (Magnolia liliiflora). Saucer magnolia is considered a small tree, or large spreading shrub. The plant is named for its distinctive wide, saucer-like flowers. It was first cultivated in 1826 by French horticulturist Etienne Soulange-Bodin. The plant entered cultivation in England, becoming popular there before being adopted in other parts of Europe, as well as North America. Saucer magnolia has since become the most popular deciduous magnolia used in cultivation.
Distribution & Habitat
Saucer magnolia is commonly used as a planting in the British Isles, especially in the south of England. It is also planted throughout the United States, particularly along the east and west coasts. Saucer magnolia develops best in humid temperate regions.
Saucer magnolia may grow into a multi-stemmed tree, or large spreading shrub. It has a medium growth rate, and is upright to rounded when young. As the plant matures, it develops a rounded, or broad spreading shape.
Saucer magnolia generally has a lifespan of over twenty years. Healthy trees and shrubs may live for 80 to 120 years.
Saucer magnolia reaches heights of 20 to 30 feet, with a 20 to 30 foot spread.
When mature, saucer magnolia features smooth, bright tan or gray bark. The plant’s bark is thin, and may be easily wounded by maintenance vehicles, or inclement weather.
Saucer magnolia has large, thick leaves that measure three to six inches in length. The leaves are dark green, with a soft, leathery texture. They are oval to circular in shape, and have smooth margins, as well as pointed tips. The underside of the leaves is fuzzy. The terminal leaf bud is soft and silky. It measures ½ an inch in diameter. The leaves turn yellow to brown in fall.
Saucer magnolia produces elegant, goblet-shaped flowers that create a spectacular floral display. Large green flower buds form at the tips of branches during winter. The buds open from late February to April, just prior to leaf expansion. Large, white flowers shaded in purple or pink emerge from the buds. The flowers resemble saucers, and are composed of six waxy petals. The petals are shaded pink to purple on the exterior, and white on the interior. The flowers generally measure five to ten inches in diameter. Each flower is perfect, with male and female parts. In late spring, additional flowers may bloom on new growth. These late flowers are usually less vigorous, and often appear pale or faded. Saucer magnolia blooms heavily when young.
Saucer magnolia yields elongated fruit. The fruit emerge from slits on the branches in August and September. They have a hard surface, and contain reddish-orange seeds.
Saucer magnolia can be grown from woody stem cuttings, or through seed propagation. To gather a stem cutting for planting, use a pruning tool to administer a cut at the end of a magnolia branch or sprout. Submerge the cut end of the branch or sprout in water. Once moistened, transfer the branch or sprout to a container filled with a mixture of soil and a rooting hormone. Maintain soil moisture for sixty to ninety days while the saucer magnolia establishes its roots.
For seed propagation, seeds can be purchased, or collected from a healthy magnolia. When taking the latter approach, inspect magnolia plants for open seed pods. Examine the interior to determine the color of the seeds. If the seeds are red, the pods may be extracted. Remove the pods from the plant with pruning shears. This will preserve the seeds, and avoid causing damage to the plant. Once the seed pods have been collected, the seeds may be gathered for use. To easily remove the seeds, store the pods in a paper bag for one to two days. This will cause the pods to become desicatted, and allow for the seeds to be extracted with greater ease. Once the seeds have been collected, they must be stratified. Wrap the seeds in a damp paper towel, and place them in a plastic bag. Store the bag in a cold location for up to ninety days. Do not exceed this time frame; seeds that remain cold for over ninety days have a lower germination rate. When the stratification period has concluded, the seeds may be removed from the plastic bag, and planted.
Saucer magnolia has a shallow root system comprised of fleshy, rope-like roots. Most of the plant’s roots develop in the top foot of the soil. The roots are thick, and unbranched. They require consistent watering during periods of drought. Applying a layer of organic mulch to the soil is pivotal to concealing the roots. Mulch also helps to conserve soil moisture, and moderate soil temperature.
Soil & Topography
Saucer magnolia grows in acidic, loamy, moist, rich, sandy, clay, and well-drained soils. Well-drained, slightly acidic soils are ideal for plant development. Saucer magnolia requires consistent sun exposure, and moisture to flourish. The plant exhibits some drought resistance. It is also relatively tolerant to wind, and alkaline soils.