There are a number growing number of gardeners who are successfully growing Southern Magnolias outside the southern United States. Their natural range is the deep south of the United States. The states in the natural range of this tree include North Carolina, South Carolina, Georgia, Alabama, Mississippi, Louisiana and Texas. In their native habitat they can become very large trees over time. There are some older trees that are over 120 feet tall. They can grow from 1-2 feet a year in good conditions which is considered a slow growing tree. Their natural shape is somewhat like a pyramid with older trees sometimes growing quite wide. This is a broadleaf evergreen tree with large shiny dark green leaves that can be 5-8 inches long and 2.5 to 5 inches broad. The flowers are very showy and large. They are white and up to 12 inches across and have a very sweet fragrance. Southern Magnolia like a well watered but not boggy location and rich soil on the more acidic side. Partial shade to full sun is ideal.
In my personal travels I have seen Cold Hardy Southern Magnolias in Columbus 6A and Lancaster 6A Ohio as well as several specimens in the Toledo Ohio 6A, 6B area. I have also seen them in Philadelphia 7B and Washington D.C. 7A Some of the specimens in Washington D.C. are very old and massive. From my research trees in the wild or trees grown from seed collected from wild trees appears to be hardy to Zone 7A.
There are several cultivars that appear more cold hardy than the wild variety. There are two cultivars I am going to mention. The first Cold Hardy Southern Magnolias cultivar is Brackens Brown Beauty. This tree develops a dense canopy with smaller leaves than the wild variety. This is the variety that I have seen planted in Ohio and is possibly cold hardy to Zone 5B. The other cultivar that I have seen tried in the north is Edith Bogue. This is a vigorous tree with a pyramidal shape. Both of these cultivars are worth trying in colder climates than wild grown trees could tolerate. These can grow to decent size trees over time but don’t expect them to get as large as they would in the deep south.
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