We have discussed the importance of planting native in the article titled "Why Native Plants?" and have gone over the top ten native perennials here. This week, we will tackle trees. Not every tree is going to do well in every location. Lighting, water levels, soil conditions, growth rate, and available space all play into which trees you should choose for your area! It is very important to remember "right plant, right place" when choosing what plant will work best for your areas. The next top 10 list will be shrubs, then we will begin to break down native plants by conditions such as sun and water.

     These lists are focused around the Pittsburgh area, so if you are reading from somewhere aside from southwestern PA, please double check all of the plants' native ranges on this list before adding it to your yard or garden. Sometimes, native ranges end abruptly, other times, they expand across entire continents. It is always best to double check! Some species may have subspecies that do better on a certain half of the continent, such as the Texas redbud (Cercis canadensis var. texensis) being a subspecies of the redbuds seen all over the eastern US into Canada (Cercis canadensis). Not every species have subspecies, but some do. These are populations that often have a specific adaptation that increase their ability to thrive in a certain geographical area, such as heat or moisture levels, for example.

     The following list is in no particular order, and all of the following trees have their own pros and cons! Let's begin with one of my personal favorite trees and one of the largest trees in eastern North America.

1. Sycamore Platanus occidentalis

Zones: 4-9

Size: 75-100' tall and wide

Sun: 6+ hours

Wildlife: specialized moths, songbirds, various insects, mammals, birds, owls

    This tree carries many common names, such as the American sycamore, buttonwood, American planetree, and western plane. The specific epithet occidentalis translates to "western," referring to the western hemisphere. This beautiful tree can grow anywhere from 75 to 100 feet tall with equal spread and a trunk diameter up to 10 feet. This tree does best when given ample room to grow, as it develops quickly. One of the most outstanding features of this tree is the exfoliating bark, revealing a smooth, white inner bark. Typically these trees will shed their brown outer bark in irregular pieces towards the top of the tree, making an interesting stark contrast to its neighbors when the leaves drop in fall and a lovely accent to the landscape until the leaves begin to flush out again in spring, providing winter interest in a way not many trees are capable of. This tree can live to be 200 years old and can be tapped for its sap, that can then be turned into syrup.

     Such a large tree carries abundant space for wildlife to make their homes! Eastern tiger swallowtail butterflies lay their eggs on the leaves, allowing their caterpillars to have an all you can eat buffet! The sycamore tussuck moth is specialized to this species of tree. One tree can host hundreds of insects at once without any significant damage to the tree. Aside from butterflies, moths, leaf hoppers, wood boring insects and more, these trees can act like a wildlife hotel throughout its lifespan. Not only do the branches provide nesting sites for all sorts of birds, the trunk of the tree often forms cavities as it ages. These cavities are used as hotel rooms for a variety of birds and mammals, including squirrels, owls, bats, wood ducks and more. Occasionally, a cavity at the base of the tree grows large enough to accommodate black bears. The tree acts as a food source for songbirds who dine on their seeds and deer who nibble the low hanging branches during winter when food is scarce. Such a large tree can host all of these animals, no problem!

2. Cherry Birch Betula lenta

Zones: 3-8

Size: 40-75 feet tall, 35-40 feet wide

Sun: 4-6+ hours

Wildlife: various moths and butterflies, birds

     You may be familiar with the species Betula nigra, the black birch or river birch, with its peeling, papery thin bark. This is a closely related relative, the cherry birch. While it doesn't have the iconic bark of the river bitch, the Betula lenta is still a beautiful tree and a valuable plant to the ecosystem. This species was previously used for birch beer and wintergreen oil, but now is mostly used as an ornamental shade tree. This tree naturally grows in cool forests and rocky outcrops. This tree shares the common name black birch with Betula nigra because of the bark of young trees. The bark of young Betula lenta is very dark, nearly black and smooth. As the tree ages, the bark will become furrowed. The bark makes a brilliant contrast with the beautiful golden fall foliage.

     This tree hosts a variety of butterflies in the caterpillar stage. Mourning cloak, dreamy duskywing, and eastern swallowtail butterfly caterpillars are often seen munching on these leaves. Megachile rubi, a solitary leaf cutter bee will also cut crescent shaped holes in the leaves to take back and use as building material for the nests of the next generation of these native bees! Songbirds will build nests in the branches. Songbirds and gamebirds will eat the seeds.

 

3. Fringe Tree Chionanthus virginicus

Zones: 3-9

Size: 12-20 feet tall and wide

Sun: 4-6+ hours

Wildlife: pollinators, bees, songbirds, small mammals

     Fringe trees are a stunning small tree, that is resistant to black walnut. Naturally, it's found growing in rich forests and streambanks. The common name, fringe tree, comes from the fragrant, white, spring blooms that attract pollinators, like bees. When in full bloom, it almost looks as if it is snowing, just around the tree. The flowers are fragrant, with male flowers being showier than female flowers, though both being beautiful. This tree is a member of the olive family and that becomes clear when the female trees begin to ripen their fruits. The fruit this tree produces olive like fruits that turn a dark blue-black color when ripe. These fruits will only appear on female trees when a male tree is close by to pollinate. The leaves turn a crisp golden color in fall.

     The flesh of the fruit is enjoyed by a variety of sonbirds, such as the cardinal, northern mockinbird, eastern bluebirds, turkey, and more. Deer will also browse the fruits. The stone of the fruit, or the seeds, are often enjoyed by small rodents such as rabbits and squirrels. Birds nest in the branches of mature trees. Various caterpillars will munch on the leaves, such as Fringetree swallow, a few species of sphinx moths, and fall webworms.

4. Paw Paw Asimina triloba

Zones: 5-9

Size: 15-20 feet tall and wide

Sun: 4-6+ hours

Wildlife: pollinators, songbirds, mammals, Zebra Swallowtail butterfly

     Pawpaw trees are an incredible fruit tree- they produce one of the largest fruits native to north america! They also host some unique pollinators. These flowers aer a deep purple color, meant to mimic the appearance of carrion to attract their pollinators- flies and beetles. The flowers contain both male and female parts, but they cannot pollinate flowers from the same tree. In order to have a tree produce fruit, there needs to be genetically different pollen reaching the flower. The fruit these small trees produce are delightful! They're edible and taste like a tropical fruit, though they have large seeds. You will find these trees growing naturally in areas such as woodlands, along streams or in ravines. The large leaves turn a beautiful, radiant gold in fall.

     As mentioned before, their pollinators consist of flies and beetles. Their fruit is enjoyed by a myriad of animals, aside from humans. Songbirds, turkeys, raccoons, opossums, black bears and foxes all enjoy the creamy fruits. This tree is also a host plant for the larval stage of the zebra swallowtail butterfly.

5. Red Buckeye Aesculus pavia

Zones: 4-8

Size: 15-25 feet tall, 10-20 feet wide

Sun: 4-6+ hours

Wildlife: pollinators, hummingbirds, squirrels

     A buckeye isn't just a delicious peanut butter cookie! You will find these trees growing naturally in moist areas, such as woodlands, ravines, and streambanks. Also called horse chestnuts, this member of the maple family puts on its show in springtime, when approximately 7-10 inch long panicles of tubular, bright red flowers make their appearance all over this small tree. These trees naturally grow in the understory. Because of this, they do best in partial shade. While they require moist soils and are not overly drought-tolerant, the soil still should be well draining. Soggy soils are not compatible with this tree, but they make wonderful additions to the rain garden.

     The impressive spring blooms draw in pollinators like butterflies, bees, and ruby throated hummingbirds. The tree branches and large leaves provide a safe place for birds to nest. Squirrels and other browsers will occasionally eat the nuts.

 

 

 

6. Striped Maple Acer pensylvanicum

Zones: 3-7

Size: 15-25 feet tall, 12-20 feet wide

Sun: 4-6 hours

Wildlife: bees, moths, browsing animals

     This maple tree has many names. Goosefoot maple, snakebark maple, striped maple, and whistlewood are among the common names used to address this tree. The leaves don't appear to be the same as many other maple leaves, as they lack the iconic maple leaf shape. This is where the name goosefoot maple comes in, as the leaves resemble that of a goose's footprint. This tree does best in partial shade and tolerates deep shade well. It is an understory plant, preferring average, slightly acidic soils. They are often found growing on cooler, north facing slopes. The leaves turn a brilliant yellow in the fall. These trees can easily live to be 100 when given the correct conditions to survive. The foliage turns a clear yellow in fall.

     It's easy to forget that maples flower. Many species of maples, including the striped maple, have insignificant flowers. That doesn't mean, however, that they are of no use to the wildlife! They are an important early source of nectar for bees. Plants in the Acer genus support the larval stage of imperial moths, a beautiful yellow and brown moth. However, this tree supports mostly browsing wildlife, or animals that nibble on the lower branches.

7. Eastern White Pine Pinus strobus

Zones: 3-8

Size: 50-80 feet tall, 20-40 feet wide

Sun: 4-6+ hours

Wildlife: Imperial moth larvae, birds, small mammals, black bears

     Identifying a white pine is easy, "white" has five letters, and eastern white pines have 5 needles to a fasicle. Fasicles are the bundles that pine needles grow from. This is the only species of pine that naturally grows east of the Rocky Mountains. Most specimens will live to be an average of 200 to 250 years old, while some will live to be over 400 years old. This magnificent tree is the state tree of both Michigan and Maine. As a young tree, it is a familiar pyramidal shape, however, as it grows, it becomes more ovate with an irregular crown. This tree does best when planted in well drained soils and does not tolerate heavily compacted soils and air pollutants, like sulfur dioxide and ozone. This tree prefers moist yet well drained, loamy soils and full sun in cooler climates. They can also be found on dry, sandy or rocky ridges. This evergreen tree is an easy way to ensure your landscape has winter interest. We aren't the only ones who enjoy an evergreen plant!

      Birds and small mammals will use the tree as cover. Nests can be found in the branches where they are easily hidden by predators by the evergreen needles. The imperial moth will lay its eggs on the needles of this tree, which will be eaten by the caterpillars. Where it serves as a key point of value to the wildlife is in the seeds. The seeds are a favorite of black bears, birds, squirrels, and rabbits. The bark is also enjoyed by beavers, rabbits and porcupines.

 

8. Bald Cypress Taxodium distichum

Zones: 4-9

Size: 50-70 feet tall, 30-40 feet wide

Sun: 6+ hours

Wildlife: small mammals, waterfowl, other birds, amphibians, catfish

     This is an unusual conifer! It gets the "bald" portion of its name by the fact that this is, in fact, a deciduous conifer. Bald cypress can be found growing wild in wetlands such as swamps, bayous, and rivers. Don't let the amount of water these plants love scare you- many of them grow well in drier soils many of us are accustomed to, yet suit the wettest areas of the yard without batting an eye... or fluttering a leaf. These are slow growing and long lived trees that typically live to 600 years or longer. This tree is excellent at helping to absorb floodwaters and to prevent erosion. Cypress needles will turn orange to gold in fall, before dropping. Cypress is also create cypress knees, or pneumatophores. These are specialized root structures that emerge upward through the ground. It is most likely due to the poor oxygen content of swampy and wet soils, so these structures help to improve gas exchange in the roots of the tree. These knees can do some serious damage to lawn mower blades, so it is best to plant these trees in areas with plenty of planted areas, like a garden or flower bed, to avoid the need to mow or walk in the area.

     Because of the unique areas in which this tree grows naturally, it can support some unusual wildlife for a tree. Cypress domes, areas of forested wetland comprising mostly of cypress trees, provide habitat for a variety of animals such as catfish, salamanders, frogs and toads. Wading birds, like herons, eat the seeds. Squirrels, turkey, ducks, warblers, and other waterfowl also dine on the seeds this tree produces. Occasionally, older trees will form hollows that house a variety of wildlife, either as cover or as a den for the season. Birds will nest in the branches of the trees.

 

9. Florida Dogwood Cornus florida

Zones: 5-9

Size: 15-30 feet tall and wide

Sun: 4-6+ hours

Wildlife: Specialized bees, butterflies, songbirds, gamebirds, mammals

     It can be hard to tell the Florida dogwood apart from the non-native kousa dogwood. The easiest way to determine which species you have is to look at the fruits. Native Florida dogwoods will have small, red berry-like fruits. Kousa dogwoods will have larger, round fruits about an inch across in diameter. The native Florida dogwood is an understory tree, staying small at about 20' tall. This tree's native range is extensive, growing naturally from Canada to Mexico along the eastern half of North America. Like other dogwoods, this tree blooms in spring with small, green flowers, surrounded by the petal-like bracts, or modified leaves. It truly is a sight to see when the tree matures! The leaves of this tree will turn a lovely deep red in fall, accompanied by its bright red berry-like fruits. The showy fruit will begin to show in August and will continue to feed wildlife through winter.

     This tree is a host plant for the spring azure butterfly, a beautiful blue butterfly you may have seen fluttering around. Three species of bee have co-evolved with this plant and specialize in pollinating this tree in particular. The fruit are enjoyed by a wide variety of animals, songbirds and game birds being the main connoisseurs. Other animals you may see snacking on the fruits include foxes, deer, squirrels, chipmunks, and black bear. Who knew such a small tree can support so many animals?

 

10. Eastern Redbud Cercis canadensis

Zones: 4-8

Size: 20-30 feet tall, 25-35 feet wide

Sun: 4-6+ hours

Wildlife: Bees, butterflies, songbirds, small mammals

     Eastern redbuds are easily spotted in spring with their proliferous purple to pink blooms that line their branches and occasionally, their trunks. Their heart shaped leaves give a lovely display in fall when they turn anywhere from golden yellow to deep red. This tree is a member of the legume family, Fabaceae. It is easy to see the family resemblance when comparing the flower shape of a pea with the flower shape of a redbud flower. The flowers and young pods are edible either cooked or raw, but if you choose to indulge in the wonderful food your tree produces, be sure to leave plenty for the pollinators and other wildlife who rely on it. Unlike other species in this family, the redbud tree does not fix nitrogen in the soil, but that doesn't mean it isn't worth adding to your landscape! As a small tree, it is perfect for many locations. It is found naturally in quite a few areas, such as the forest understory, abandoned fields, roadsides, rocky bluffs, and along stream banks. This plant is a seriously tough cookie, also tolerating damage caused by deer, clay soils, even juglone toxicity. Juglone is the chemical that is produced by all parts of the black walnut tree, another wonderful native tree. This chemical is what makes it hard for many species of plants to survive under their canopies.

     Possibly due to the amount of niches in the ecosystem and how widespread this plant is, redbuds host many species of native wildlife. This tree supports bees and butterflies with the spring flowers, but also with its foliage. If you see C shaped holes taken out of the sides of the leaves, that is a sure sign of leafcutter bees! Redbud trees are a favorite source of leaves for these bees, which they use to create their nests. They have a much more mild temperament than honeybees and sting far less frequently. Their sting is also more mild. Aside from supporting bees in more than one way, they also host at least 12 species of moths and butterflies. Caterpillars will munch on the leaves during spring, where leafcutter bees will begin building their homes in late summer and fall, so no worries about your tree looking like Swiss cheese! Songbirds, including bobwhite quail, and small mammals browse the seeds. While deer will nibble at the lower branches, they do not cause serious damage to the tree. The branches also give areas for small birds to nest.

 

     Trees are some of the most important parts of the ecosystem. They help to control temperatures by cooling the area beneath them, provide lots of vertical habitat for the wildlife, and some provide a seemingly endless food supply to wildlife. There really isn't anything quite like a forest bustling with life, but they are falling in both numbers and area with how many are being diminished with human expansion. While planting a few trees in a landscape does not a forest make, it is absolutely better than invasive, nonnative, or no trees in the landscape.

 

Works Cited

American Fringetree (Chionanthus virginicus). Illinois Wildflowers. (n.d.-a). https://www.illinoiswildflowers.info/trees/plants/fringetree.html

American Sycamore (platanus occidentalis). Illinois Wildflowers. (n.d.-b). https://www.illinoiswildflowers.info/trees/plants/am_sycamore.htm

Bald Cypress. National Wildlife Federation. (n.d.). https://www.nwf.org/Educational-Resources/Wildlife-Guide/Plants-and-Fungi/Bald-Cypress

Betula lenta - Cherry Birch. Native Plant Trust: Go Botany. (n.d.). https://gobotany.nativeplanttrust.org/species/betula/lenta/

Cercis canadensis. Cercis canadensis (American Judas Tree, American Redbud, Eastern Redbud, Redbud) | North Carolina Extension Gardener Plant Toolbox. (n.d.). https://plants.ces.ncsu.edu/plants/cercis-canadensis/

Cornus florida. Cornus florida (Flowering Dogwood) | North Carolina Extension Gardener Plant Toolbox. (n.d.). https://plants.ces.ncsu.edu/plants/cornus-florida/

Immel, D. L. (n.d.). Eastern Redbud. Retrieved June 15, 2023,.

McNiel, R. E., & Carpenter, P. L. (1974). Nitrogen fixation by Woody plant species as measured by the acetylene reduction assay1. HortScience, 9(4), 381–382. https://doi.org/10.21273/hortsci.9.4.381

Pinus strobus / Eastern White Pine. American Conifer Society. (n.d.). https://conifersociety.org/conifers/pinus-strobus/

Platanus occidentalis. Missouri Botanical Garden. (n.d.). https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a891

Striped Maple. Acer pensylvanicum L. (n.d.). https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/acer/pensylvanicum.htm

Williamson, A., & Williamson, J. (2014, February 21). Buckeyes and Horsechestnuts. Home & Garden Information Center | Clemson University, South Carolina. https://hgic.clemson.edu/factsheet/buckeyes-horsechestnuts/