February Plant Spotlight: Star & Saucer Magnolia
In late winter and early spring there are a couple of magnolia trees that put on a beautiful flower display letting us know that Spring is just around the corner: Star Magnolia (Magnolia stellata) and Saucer Magnolia (Magnolia x soulangiana). When one says magnolia we usually first think of the southern magnolia (Magnolia grandiflora) with its large white flowers in the summer. There are actually about 125 magnolia species. Some are native to the United States while others are native to Mexico, Central America, the West Indies and Asia. The star and saucer magnolias are popular in the landscape because they are one of the earliest trees to bloom in late winter and early spring.
The star magnolia (Magnolia stellata) can be grown as a small, deciduous, multi-stemmed tree or a dense, oval-to-rounded shrub that grows 15 to 20 feet tall and 10 to 15 feet wide. Star magnolia is a slow grower only growing 3 to 6 feet over 5 to 6 years. In late February and March, star magnolia puts on a lovely flower display before the leaves appear. The flowers are small (3 to 4 inches in diameter) compared to other magnolia species. Star magnolia flowers are pink or white and fragrant with strap-shaped petals. This magnolia is cold hardy to zone 5 (Wayne County is in zone 8) however it is not uncommon for the flowers to be damaged by a late winter or spring freeze in our area. Star magnolia is also not tolerant of shade.
There are several cultivars of the star magnolia. ‘Centennial’ has flowers with slight pink on the outside. ‘Rosea’ has pink flower buds that fade to white flowers. A note of caution with ‘Rosea’ is that there is more than one clone with this name so buy the plant when it is in flower to ensure the desired color. ‘Royal Star’ has flower buds that are faintly pink that open to large double, white fragrant flowers. ‘Waterlily’ is very fragrant white flowers and blooms little later than other star magnolia cultivars.
The saucer magnolia (Magnolia x soulangiana) is a hybrid of two other magnolia species. It can also be considered a large, spreading shrub or a small tree with low, wide spreading branches. Saucer magnolia can grow to 20 to 30 feet tall and wide. This deciduous tree grows at a medium rate of about 1 foot per year. Saucer magnolia is a deciduous tree that will flower in late February and March before the leaves come out. Like the star magnolia, saucer magnolia can also be damaged by a late winter or spring freeze and is more cold sensitive than star magnolia. Saucer magnolia can tolerate some partial shade but would prefer full sun. The flowers of saucer magnolia are large and white with tints of pink to purple depending on the cultivar.
There are many cultivars of saucer magnolias to choose from. ‘Brozzonii’ is a larger plant (25 to 30 feet tall) that blooms later than other saucer magnolias and has large, white flowers that are pink at the base. ‘Lennei’ has huge flowers that are white inside and dark purple outside. It blooms later and can sporadically on into spring. ‘San Jose’ blooms early and has large, rosy purple flowers.
Both star and saucer magnolias work well in the landscape as a specimen plants being the focal point of a landscape bed. The care of both magnolias will be similar. They prefer rich, acidic (pH 5.5 to 6.5), well-drained soils. Both are moderately drought tolerant and saucer magnolia can tolerate some slightly wet soils. To help protect the flowers of both magnolias from freeze avoid planting it in a southern exposure where flowers would open earlier and protect from late winter winds that may damage flowers. Magnolias generally have little pest problems. Star and saucer magnolia can be susceptible to powdery mildew. To help control, prune branches to improve air circulation and rake up dropped foliage in the fall. Scale insects can occasionally be a problem that can be managed with horticultural oil sprayed in late winter and early summer.
As you notice the star and saucer magnolia blooming in people’s landscape, you may consider adding one to your own landscape. Even with the flowers being susceptible to a spring freeze, they are still worth having to see those first flowers of the year and be reminded that spring is just around the corner.