Sun Requirements for Magnolias

Native Magnolia Trees

• The cucumber tree, Magnolia acuminate, handles zones as cold as U.S. Department of Agriculture plant hardiness zone 3. This tall magnolia, capable of maturing to 80 feet high, grows in partly shady to full sun sites, generating aromatic green-white flowers and interesting fruit that resembles cucumbers. Another North American magnolia, the southern magnolia, or Magnolia grandiflora, does well in partial shade. It cannot survive in areas colder than zone 7, but it appreciates some protection, especially from the hot sun of summer.

Nonnative Magnolia Trees

• Called the Yulan magnolia, Magnolia denudata is a Chinese species that requires warm climates. It grows in full sun or partial shade in USDA zones 6 through 9, reaching 30 to 40 feet tall, which makes it suitable for smaller yards. Yulan magnolia takes as long as seven years to generate its initial flowers, notes the Missouri Botanical Garden. Japan's kobus magnolia, Magnolia kobus, blooms in March or April in USDA zones 5 through 8. It does well in full sun or some shade, but its early blooming period is a consideration when placing it. Full sunshine can trigger it to bloom too soon, in late winter, if you put it in a site with southern exposure.

Hybrid Magnolia Shrubs

• Magnolia "Ann" is a hybrid magnolia shrub cross from the 1950s with a later blooming period than other magnolias, thus helping it to avoid loss of flowers from a spring frost in zones 4 through 8. Still, refrain from putting it close to the house on a southern exposure, or a warm late winter day in full sun can trick the flowers into turning out. Ann grows to 10 feet, while Magnolia Jane is taller (to 15 feet). Jane also has the same sun requirements as Ann, full sun or partial shade, but not too close to the home when facing south. Keep both these shrubs protected from the wind for the sake of their foliage.

Nonnative Magnolia Shrub Cultivars

• Magnolia stellata is the scientific name of Japan's star magnolia. Two attractive cultivars of this shrub are Royal Star and Waterlily, with both appropriate for USDA zones 4 through 8. Both types can grow to 20 feet in partly shaded areas or sunny ones, with their early blooming periods presenting possible problems if you put them where sunlight can induce the buds to open prematurely. A frost can then kill the flowers. Put waterlily in full sun rather than partial shade for the best flowering effect.