Bigleaf magnolia, Magnolia macrophylla, has the largest flowers and leaves of any native plant in North America.
If you live in the southeastern United States, you will find bigleaf magnolia growing as an understory tree in the Appalachian mountains.
Magnolia macrophylla is also known as large-leaved cucumber tree, umbrella magnolia, and cowcumber tree.
Bigleaf magnolia is a stunningly beautiful tree, rarely grown in American gardens. It is under pressure or endangered in North Carolina, Ohio, and Arkansas. You can plant one of America’s most beautiful and unusual trees while perhaps helping protect the species.
Having grown Magnolia macrophylla I can assert it does not like the combination of full sun and dry soil conditions. Bigleaf magnolia is an understory tree growing 40-60 feet tall. Full sun at higher elevations, partial shade, and full shade if the canopy light is filtered are all acceptable. Bigleaf magnolia does not care for heavy shade at all.
Regarding moisture levels, once Magnolia macrophylla is established it does not need anything more than normal rainfall amounts.
It is native to the forests of the eastern United States (and parts of Mexico). Winter hardy zones 5-8, it tends to have a thick trunk, most likely evolved to support the weight of all of those huge leaves.
Magnolias are an old species of tree, and the large flowers and leaves do indeed look prehistoric.
The flowers are pollinated by beetles – bees and butterflies did not exist when Magnolia macrophylla evolved.
Growth is quite fast when young, especially if there is ample moisture. Like rhododendrons, another species found often in the Appalachians, it does not tolerate poorly drained soils. In addition, windy conditions can shred the gigantic leaves, so protect from areas exposed to lots of wind.
Winter hardiness zones: 5-9
|Common name(s)||bigleaf magnolia|
|Of note||can be grown in heavy shade|
|Water requirements||moist soil conditions, high|
|Soil quality||rich, well-drained|
|Suggested use(s)||naturalized, shade gardens, understory, woodlands|
|Hardiness zone(s)||5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b|
|Deciduous or evergreen||deciduous|
|Bloom period||mid to late spring|
|Exposure||afternoon shade, filtered light, full shade|6