Saucer magnolia tree (Magnolia x soulangiana) blooms in various shades of white, red, purple and pink in containers, yards and landscapes throughout U.S. Department of Agriculture (USDA) plant hardiness zones 4 through 9, where, depending on the cultivar, it is hardy. Although most saucer magnolia trees produce colorful flowers in bright or pastel hues, some cultivars bloom mostly in white. Deciduous with wide-spanning limbs, saucer magnolia usually grows 20 to 30 feet tall and wide. A healthy specimen grows about 1 foot each year.
White-flowered saucer magnolia cultivars may have snowy white blooms, but their inner buds often have shades of light pink or purple. The cultivar “Alba” (Magnolia x soulangiana “Alba”), hardy in USDA zones 5 through 9, produces mostly white, showy flowers about 5 to 10 inches long. The flower petals are white, but like “Superba Alba” (Magnolia x soulangiana “Superba Alba”), also hardy in USDA zones 5 through 9, the flowers feature pale shades of pink at the base. “Alba” saucer magnolia's leaves turn from green to yellow in fall. “Candolleana” (Magnolia x soulangiana “Candolleana”), hardy in USDA zones 4 through 9, grows 15 to 20 feet tall and produces white and off-white flowers. “Lennei Alba” (Magnolia x soulangiana “Lennei Alba”), perennial in USDA zones 5 through 8, has pure-white, late-blooming flowers. Other white- or off-white-flowered cultivars suitable for USDA zones 5 through 9 include “Alexandrina” (Magnolia x soulangiana “Alexandrina”) and “Amabalis” (Magnolia x soulangiana “Amabalis”).
White, Pink and Lavender
Saucer magnolia cultivars with white petals usually have pink or lavender at the flower base. “Brozzonii” saucer magnolia (Magnolia x soulangiana “Brozzonii”), hardy in USDA zones 5 through 8, reaches 25 to 30 feet tall, and its late-blooming flowers are white with lavender-pink at the base. “Dottie Grosse” (Magnolia x soulangiana “Dottie Grosse”), perennial in USDA zones 4 through 9, produces mostly white flowers with shades of pink and lavender; the tree grows 20 to 30 feet high. The cultivar “Grace McDade” (Magnolia x soulangiana “Grace McDade”), hardy in USDA zones 5 through 9, has rounded flowers with white petals inside and lavender-pink coloring outside. “Grace McDade” saucer magnolia can live 80 or more years.
Saucer magnolia trees can have white petals mixed with bright colors, including several cultivars hardy in USDA zones 4 through 9. An example is “Rustica Rubra” (Magnolia x soulangiana “Rustica Rubra”), which has cup flowers with white on the inside and scarlet on the outside; the tree grows 20 to 30 feet tall. “San Jose” (Magnolia x soulangiana “San Jose”) is another example. It blooms in early spring with large, scented flowers that include magenta and purple. “Speciosa” (Magnolia x soulangiana “Speciosa”) is a late-flowering cultivar with purple-enhanced white flowers. “Lombardy Rose” (Magnolia x soulangiana “Lombardy Rose”) has long, deep-pink petals.
Hardy in USDA zones 5 through 8, “Verbanica” saucer magnolia (Magnolia x soulangiana “Verbanica”) produces flowers that have rosy red petals with white tips. It is a slow-growing tree that blooms in late spring.
Depending on weather conditions, a saucer magnolia growing in full sun to partial shade usually blooms in March or early to mid-April. The tree performs best in well-draining, sandy or loam soil with pH of 5 to 6.5. Frost can turn its flowers prematurely brown. Some saucer magnolia cultivars keep their green leaves in fall, but others' leaves change to yellow. Saucer magnolia does not attract many insects, but scales can affect its twigs, and weevils may chew on its foliage. The tree is susceptible to fungal leaf spots, cankers and Verticillium wilt.