As I write this column, Marjorie and I are nearing the end of a 12-day vacation that included a day at Longwood Gardens in Kennet Square, Pennsylvania, several excursions into the Blue Ridge Mountains of North Carolina, and a day at the North Carolina Arboretum in Asheville, NC. The North Carolina end of this trip spanned three full days of southern hospitality at its best, as we were guests of Marjorie’s sister, Nancy Hipps, and her husband, Andy, as well as their son, Kevin and his fiancee, Bentley. Kevin and Bentley’s three-month-old English bulldog, Nana, was a constant source of joy and laughter.
With Andy at the wheel, we made daily excursions into the heart of autumn at its peak, mountainsides ablaze with the brilliant reds of southern dogwoods, maples and sourwoods, the bright golds and yellows of redbuds and birches, the muted reds, browns and yellows of oaks. The arboretum visit, along with several roadside stops, created the opportunity for a reunion with old friends, the trees and shrubs of the Southeastern U.S.
I had not seen a sweetgum in autumn, for example, in nearly three decades, not since teaching horticulture at a South Carolina technical college. The same could be said for several other tree and shrub species native to the Southeast, plants whose species names had faded from memory, replaced by the epithets of New England flora. All of the old names came flooding back, however, as I discovered these plants growing in both wild and managed landscapes.
The following is an account of four old friends found growing in the North Carolina Arboretum, plants that I had not seen in decades, yet each is capable of gracing gardens in USDA Zones 5 and warmer.
Sweetgum (Liquidambar styraciflua)The sweetgum tree is native from Florida to Connecticut and cold hardy through the southern areas of USDA Zone 5, so I’ve often wondered why we see so few of them in mid-coast and southern Maine. The answer could be their spiny woody fruits that remain on the tree through winter and then litter the ground in winter and early spring. As a boy in west central Georgia, I remember having to put shoes on when I mowed the grass beneath these trees. And I recall many of these fruits, each about an inch and a half in diameter, being spray-painted red and green for Christmas decoration. The glossy deep green summer leaves of sweetgums are long-stalked with toothed margins, each leaf divided into 5 to 7 pointed, star-shaped lobes. The distinctive fall foliage of sweetgums is a rich blend of yellows, oranges, purples, and reds, although I recall trees in Georgia that were consistently all yellow each autumn.
I’ve missed these trees of my youth and it was a delight to see them growing wild along the roadsides and planted along village streets and roadsides. At the North Carolina Arboretum, I encountered ‘Slender Silhouette’, a fastigiate cultivar of sweetgum, its leaves just turning to bright yellow and purple. It is the perfect tree for narrow spaces in the garden.
Dawn Redwood (Metasequoia glyptostroboides)A large deciduous conifer native to central and western China, the dawn redwood has been growing on Earth for over 50 million years, yet it was not until 1941 that it was found in the wild. Seeds planted at the Missouri Botanical Garden in 1947 produced trees that are now over 70 feet tall, so we can safely refer to this species as fast-growing. Dawn redwoods are related to two other deciduous conifers, the bald cypress of southern swamps and the giant sequoias of California.
The needles of dawn redwoods are linear, feathery, and fern-like, emerging light green in spring and maturing to deep green in summer. In fall, the needles turn to a rich red-bronze. At the North Carolina Arboretum, I found several of these trees in the transition from summer green to autumn red. The mixture of light green and orange-red produced a truly lovely sight.
Dawn redwoods are winter hardy in USDA Zone 4, yet we see so few of them in northern New England. The reason for their scarcity is a mystery, for they are among the most beautiful of trees. They make excellent street trees, yet are also perfect for rain gardens and other wet areas. Young trees can be grown for several years in large containers, then planted into the garden.
Green Hawthorne (Crataegus viridis ‘Winter King’)Hardy to USDA Zone 4 and one of the most disease resistant hawthorns, green hawthorn is a native plant from the southeastern U.S. from Virginia to Florida, westward to Texas and northward to Illinois. I have seen the cultivar ‘Winter King’ in New England botanical gardens, but seldom in private gardens, despite its ease of culture, drought tolerance, and lack of spines. Topping out at 20 to 35 feet in height with a broad crown, it is a good fit for smaller gardens. The leaves of ‘Winter King’ are a dark glossy green in summer, turning purple to red in fall. The fragrant white flowers appear in 2-inch clusters in early spring and are followed by small red fruits (sometimes referred to as “haws”) that ripen in late summer and persist on the leafless tree will into winter, eventually taken by birds.
When we arrived at the North Carolina Arboretum, leaves of the ‘Winter King’ hawthornes had already dropped, leaving silver-barked stems crowded with bright red fruits.
Beautyberry (Callicarpa dichotoma)To come across an understory shrub with lilac-violet berries is a rare event, yet I recognized such a plant at the North Carolina Arboretum at first glance and instantly recalled its name. Callicarpa dichotoma is a deciduous shrub that grows to about 4 feet in height and width. It performs best in well-drained soil, full sun to part shade. In USDA Zone 5, it should be planted in a protected area to minimize winter damage to the above-ground stems. Alternatively, it may be grown like an herbaceous perennial, pruning back the stems to 6 inches in late winter each year. The best fruit production occurs when several plants are grown together.
The stems of this beautyberry have an arching branching habit, bending downward and often touching the ground. From September through October, they are covered with the lilac-violet fruits, truly the most ornamental season for this species as the flowers, pink to lavender in color, are very small. The leaves turn yellow in autumn.
Each of these four wood plants can be successfully grown in New England Gardens. In USDA Zone 5, the location of Marjorie’s Garden, careful siting is required for the beautyberry and sweetgum, while dawn redwoods and ‘Winter King‘ hawthorne can be grown in USDA Zone 4. Yet all four species are rarely seen in Maine private gardens. After my recent reunion with these garden-worthy plants, I would encourage readers to give them a chance to grace their gardens. Next week I plan to write about other garden-worthy plants that Marjorie and I encountered on our recent travels.