Magnolia macrophylla, commonly called bigleaf magnolia, is noted for its huge oblong-obovate leaves (to 30 inches long) which are the largest simple leaves of any tree indigenous to North America. Leaves are green above and silvery-gray below. This unusual tree is rarely found in the wild, being limited mainly to a few rich wooded areas in river valleys and ravines in the southeastern United States. It is a pyramidal tree that develops a spreading rounded crown with age, typically growing 30-40’ tall. Fragrant, open, cup-shaped flowers to 8-10” (less frequently to 12”) wide bloom in May. Flowers are white with rose-purple at the petal bases. Although quite large, the flowers are often located far off the ground and are not always easy to see close up. Flowers give way to spherical cone-like fruits which mature to red in late summer, releasing individual red coated seeds suspended on slender threads at maturity. Best grown in moist, organically rich, well-drained loams in full sun to part shade. Hardy in zones 5-8.
Growing Instructions for the Bigleaf Magnolia
The seeds have a period of dormancy and need to be cold stratified to break their dormancy. The seeds are stored in a refrigerator so they have already been stratified. The seeds need to be planted when received or stored in a refrigerator until they are planted. 1. Scarify the seeds by nicking or sanding the seed coat. 2. Soak the seed in water for several hours. 3. Fill a pot with potting soil. Use a pot that has drainage holes in the base. 4. Sow the seeds on the soil and cover them with a thin layer of soil. 5. Water the container and leave it to drain. 6. Put the pot in a warm, sunny area. 7. Water the pot regularly so that the soil is moist but not wet. 8. The seedlings can be transplanted when they are a few inches tall.