Exotic-Looking Native Trees That Belong in Every Southeast Landscape
The first thing to remember about "exotic native trees" is that it does sound contradictory․ Exotics‚ by definition‚ are from other continents․ Natives‚ like the trees described in this book‚ evolved here in North America․ What most people mean when they say that are the native trees that have very exotic flowers‚ unusual leaves‚ unique bark‚ and colors in the fall that seem too bright not to be a native plant․ Tennessee and the Southeast grow some of the most exotic-looking native trees found anywhere in the U․S․ and they don't have to be kept in greenhouse conditions‚ either․ Here are eight show-stoppers native to North America and how each might fare in the Zone 6-7 growing conditions typical for Middle and East Tennessee․
Red Maple (Acer rubrum)
The Red Maple is the most exotic tree on the planet for its one stroke of genius: overnight in October‚ the five-lobed leaves turn orange‚ scarlet‚ and burgundy․ Native as far north as Newfoundland and as far south as Florida‚ the hardiest Red Maple is as comfortable in a back yard in Nashville as it is in a beach house near the Gulf of Mexico․
Red Maples will grow in full sun or part shade at a rate of 3-5 ft (1-2 m) per year‚ reaching 40-60 ft (12-18 m) at maturity․ They can grow in virtually any pH‚ but dislike soil compaction‚ which is common in urban settings․ Give maples room for roots to spread․ The seeds are eaten by birds and squirrels‚ and the red twigs help make the tree easily recognizable in winter when many other trees are leafless․
Eastern White Pine (Pinus strobus)
If you prefer stately conifer trees with soft and feathery needles over the stiff and prickly needles that are often used to define pines‚ the White Pine can grow to become the tallest tree in eastern North America․ Individual trees can exceed 150 feet tall‚ at least before old growth logging began in the colonial era․ Today a mature individual in a home landscape typically grows to heights of 50-80 feet․
White Pines thrive in well-drained‚ slightly acid soils‚ in which they grow quickly‚ 1 to 2 feet (30 to 61 cm) a year․ They are not suited to compacted or clay-heavy soil without improving‚ nor to road salt or heavy air pollution and should not be planted near driveways․ As a windbreak or privacy screen‚ however‚ few native trees can equal it as an attractive and graceful shrub․
Tulip Tree (Liriodendron tulipifera)
The Tulip Tree‚ Tennessee's state tree‚ has bright yellowish-green tulip-shaped flowers with orange at the base․ One of the tallest hardwood trees in the eastern United States‚ it grows to 90 ft (27 m) or more․ The flowers are inconspicuous‚ blooming in May high in the canopy․ Tuliptrees should be planted where they can be readily seen‚ such as from a second-story window․
It is a super-fast growing hardwood which can reach 3+ feet (1 m) in a decade‚ preferring deep‚ moist‚ well-drained soil and is not well-suited to shallow‚ compacted soil․ Unencumbered roots are important for long-term viability‚ otherwise the tree becomes susceptible to storm damage as it matures․
Ginkgo Biloba‚ a quick clarification
Ginkgo is usually found in reference lists of native trees‚ but it is not native to the United States․ It is a native of China and has never grown in the wild here․ It has been so widely planted since colonial times that it could be seen as belonging‚ and would make a good case for itself‚ with its fan-like leaves and bright golden fall color․ It is not a native for your project to document‚ however‚ if botanical accuracy is what you require․
Eastern Redbud (Cercis canadensis)
Redbud is the tree that convinces skeptics that native plants can be every bit as bright as anything you would find in a specialty catalog․ Flowers appear in early spring before the leaves leaf out‚ making a small (20-30 feet) tree pack an enormous punch․ Magenta-pink flowers cover the branches․
Redbuds tolerate more shade than most other flowering trees‚ making them useful for planting beneath taller oaks or maples․ They are also drought-tolerant‚ once established (after about two growing seasons‚ in most cases)․ TN Nursery sells Redbud as a specimen tree as well as smaller sizes to be used as a foundation planting‚ as it does not grow so wide as to dwarf a house․
Catalpa Tree (Catalpa speciosa)
It is a wonder catalpa is not more widely planted․ The orchid-like white flowers of late spring are startlingly white with purple and yellow throats like some tropical import․ The long bean-like seed pods persist over the winter‚ giving the leaf-less tree a narrow and impressive profile․
On the other hand‚ if you like a faster growing tree‚ reaching 40-60 feet‚ to rapidly provide shade‚ then catalpas are for you․ The larger species have pods and also drop large leaves‚ however‚ so if you don't like to rake‚ consider keeping them away from your patio․
Overcup Oak (Quercus lyrata)
Overcup Oak is not nearly as showy as Redbud or Tulip Tree‚ but it deserves listing here as it is one of the few oaks that will grow well in seasonally flooded‚ chronically wet‚ or poorly drained sites․ If you have a low spot in your yard where other trees won't grow‚ this tree is your answer․ It grows to be 35 to 50 feet tall with a rounded crown․ The acorns feed deer‚ squirrels‚ rabbits‚ beavers and wood ducks․
Weeping Willow (Salix babylonica)
The Weeping Willow‚ with its drooping branches‚ might have been imported from an antique garden painting․ Willows have naturalized in American wetlands‚ on pond shores and riverbanks․ The plant is a fast-growing species that can grow 3 to 8 feet (0․91 to 2․44 m) per year and prefers evenly moist soil‚ such as along a pond‚ stream or marshy place․
Putting These Together in a Southeast Landscape
The beauty of planting the trees in this post is that you will have visual drama without fighting your climate zone․ A Redbud under a Tulip Tree adjacent to a Red Maple (the fall color tree) along with a saturated Overcup Oak can hold your wet corner of the yard while giving you an entire year of color in trees that already thrive in Tennessee summers and winters․ Most of them are at the TN Nursery․
