River birch in winter

River Birch, Red Birch

River birch
G. Lumis
Bark of river birch
G. Lumis
Leaf of river birch
G. Lumis

Scientific Name: Betula nigra

Summary
Foliage: Triangular green leaves with toothed edges, yellow fall colour
Bark: Salmon-colored bark that peels; lighter in color than the native river birch
Height: 40 to 70 feet
Spread: 40 to 60 feet
Shape: Pyramidal or oval, often multitrunked
Growth Characteristics: Fast-growing

The River Birch is often chosen for its attractive bark and ability to resist disease. The colourful, peeling bark will add interest to a winter landscape. A good tree for landscaping properties, especially at the edges of ponds and streams or in low areas.

Plant Needs
Zone: 4a-9a
Light: Full to partial sun
Moisture: Best in moist soil, tolerates heat and drought once established
Soil Type: Prefers acid and moist soil but will adapt to clayey, wet soil

Care
Transplanting should be done in early spring. Fertilize once or twice per year with a specially formulated fertilizer for Birch trees. Water to keep the soil wet or moist a few inches below the surface. Prune off lower branches to reveal the attractive bark but do not prune during the growing season. Rather, wait until the end of the growing season in the fall. This is especially important because the bronze birch borer is active during the spring and open pruning wounds are inviting to them.

Problems
Although resistant to Bronze Birch Borer, it is susceptible to limited Birch Leafminer attacks.

Iron deficiency may occur, especially in alkaline soils. This is evident by yellowing of the leaves. This problem is refered to as Chlorosis and can be treated by introducing iron tablets into the soil.

One Messy Son Of A Birch

River birch. Photo: fastgrowingtrees.us

Faithful reader Penny asks, “Is there anything more messy than a river birch? I’m constantly raking leaves and picking up branches. Any suggestions for this devil?”

That’s one helluva good question, Penny. Yes, there are things messier than a river birch. Monkeys, for instance. Ever looked in the monkey cage at the zoo? Feeling queasy just thinking about it. I hate monkeys. But back to river birch.

River birch (Betula nigra) belongs in the category, “Beautiful Trees for Someone Else’s Yard.” They’re popular here in the South because they’re native, grow fast, develop handsome flaking bark, and don’t fall victim to all the borers, bugs, and diseases other birches do. People plant them for quick shade and they get it — along with problems they hadn’t expected.

For one, think river birch gets BIG — up to 80 feet tall and 50 feet wide. This is too big for the average yard, especially when you consider how close to the house lots of people mistakenly plant it. And in Grumpy’s opinion, the bigger a river birch gets, the less attractive it looks. Kinda like most child movie stars.

And then there’s the mess. River birch drops something almost every day, whether it’s small twigs, pieces of bark, catkins, or yellowed leaves. The bigger it gets, the more junk it drops, and it never stops — unless you finally get so teed off you cut the sucker down.

Other Trees To Avoid The following trees aren’t bad choices everywhere, just bad choices for the average residential yard. (They may be fine for parks or the woods, though.) I’ve listed the reasons why for each.

Ash (Fraxinus sp.) — The emerald ash borer has already killed gazillions of ashes in the Midwest and will probably wipe them out everywhere, for all intents and purposes. Not worth the risk of planting at this point.

Black cherry (Prunus serotina) — Birds eat messy fruits and splatter everything beneath them with purple poop; seedlings come up all over; favorite food of Eastern tent caterpillar, which often defoliates it.

‘Bradford’ callery pear (Pyrus calleryana ‘Bradford’) — Most over-planted ornamental tree in the U.S.; gets too big (50 feet tall and wide); very weak-wooded and prone to storm damage; white spring flowers smell like fish; thorny seedlings come up everywhere.

Chinaberry (Melia azedarach) — Drops messy fruits and seeds itself all over; invasive.

Cottonwood (Populus deltoides) — Messy, cottony seeds; aggressive surface roots; suckers profusely; weak-wooded.

Dawn redwood (Metasequoia glyptostroboides) — Nice tree, but much too big (up to 90 feet tall); develops large surface roots with age.

Hackberry (Celtis occidentalis) — Messy fruits; drops twigs; insects feeding on leaves drip honeydew on everything below and then black, sooty mold grows on the honeydew.

Pecan (Carya illinoiensis) — Grows way too big (70 feet tall and wide); drops nuts; prone to toppling in high winds; plagued by many insects and diseases.

Sweet gum (Liquidambar styraciflua) — Covers the ground in fall and winter with spiny seed balls, the most hated seeds in creation.

Southern magnolia (Magnolia grandiflora) — Grows too big (up to 80 feet tall and 60 feet wide); drops leaves 365 days a year (366 days in leap-years); develops surface roots; impossible to grow anything beneath it.

Sycamore (Platanus occidentalis) — As the Donald would say, “It’ll be YUGE!” Up to 100 feet tall and almost as wide; drops seed balls and flaking bark; prone to anthracnose fungus that causes leaves to drop.

Weeping willow (Salix babylonica) — Quite possibly THE WORST TREE OF ALL to plant in a typical yard. Aggressive roots invade water lines and lift up pavement; grows 50-60 feet wide with branches hanging all the way to the ground; weak-wooded; host to just about every insect and disease there is; without constantly moist soil, it sulks, quickly declines, and croaks (the best of all possible outcomes).

River birch, Betula nigra, has graceful form and attractive bark.

There are many species of birch native to the northern hemisphere. Betula nigra is one native to flood plains and swamps of the eastern US. This primarily streambank tree is most abundant in the hot, humid Southeast, but ranges from New England to northern Florida, and as far west as southern Minnesota and east Texas (zones 4-9). In Wisconsin its natural northern limit is the terminal moraine of the last glaciation. This tree usually goes by the common name river birch, but it is sometime referred to as water birch. The species name nigra refers to the black color of the mature bark of the wild species.

This deciduous tree has limited usefulness for timber, but because of its graceful form and attractive bark it is frequently used in ornamental plantings in decidedly less moist conditions from which it originated, especially at the northern and western extremes of its natural range. It is one of the very best fast-growing shade trees, valued as a landscape tree for the colorful exfoliating bark which is particularly noticeable in the winter. It is one of the most culturally adaptable and heat tolerant of the birches and a good substitute for pest-prone paper and white birches. Another appealing feature is the shimmering contrast when the leaves flutter in the wind, revealing a lower leaf surface of a different color than the upper surface.

River birch is a medium to tall tree, growing 60-80 feet at maturity and about 40 wide. Trees typically live 50 -75 years. The trunk typically grows about 2 feet in diameter, but occasionally will be much wider. This shade tree has highly symmetrical branching and upright pyramidal to upright oval form. Although it naturally forms just a single trunk, it is frequently sold in multiple-trunked form with two to five trunks per tree.

River birch in winter, spring, summer and fall.

The bark on the trunk varies a lot among individual plants, ranging in color from silvery gray-brown to pinkish-brown when young, but always with darker, narrow, longitudinal lenticels. It is either scaly or peels off in curly papery sheets or flakes of gray, brown, salmon, peach, orange, and lavender. More mature trunks are rough and irregularly dark gray with deep fissures that may have some pink color in the crevices. Branches on older trees tend to be a smooth and shiny gray with much darker bark on the trunk. The very slender new twigs are a red-brown color, while thin branches are cinnamon-colored with many lenticels. Older branches may also be exfoliating – typically in a gray-brown-light orange mixture on the species form, but in shades of cream, light orange, and lavender on selected varieties. The branches are not brittle, so are not prone to wind or ice damage. But twig and branch die-back is not uncommon and these dead parts tend to be messy as they shed readily.

The branches of river birch are smooth with many lenticels (L), but the trunk and older branches are scaly or peeling (C and R), with variable color.

The leaves are diamond-shaped.

The leaves are typical of a birch – alternate, diamond-shaped, with a doubly serrated margin. They are a shiny, medium green color on the upper surface and a slightly paler, more silvery color on the underside. In the fall leaves may turn a bright golden yellow, but often the fall color is dull and brownish-yellow. Leaves may also fall throughout the summer if the tree doesn’t get enough water. This species is a larval host plant for mourning cloak butterflies.

River birch in bloom (L) with the male catkins most noticeable (R).

River birch is monoecious (separate male and female flowers on the same plant) with flowers arranged in catkins. The 3″ pendant male flowers are much more noticeable than the shorter, erect female catkins. The brownish male catkins occur in clusters at the ends of the twigs. They form in fall and mature to release pollen the following spring. Because the flowers are wind pollinated, the male catkins produce abundant pollen (a significant cause of seasonal allergies in the spring). The male flowers are shed soon after the pollen is released. The inconspicuous green female catkins occur on spur-shoots and appear with the leaves.

The male catkins are formed in fall (L) but mature in spring (R).

A female catkin.

River birch seeds.

The numerous winged seeds mature in late spring (unlike all other birches which produce seed in the fall), packed between the bracts of the female catkins. The seeds are the largest of all birches native to the US. Heavy seed production occurs almost every year.

River birch seedling (L) and very young plant (R).

Seeds are disseminated by wind and water, germinating readily in moist soil. Seedlings grow quickly, so can be a bit “weedy” in the landscape. Many birds, including chickadees, song sparrows, wild turkey, pine siskins, and finches, eat the seed. The species can be propagated from seed, but commercial supplies are produced primarily from stem cuttings.

In early spring the tree produces copious amounts of sap, which Native Americans collected and boiled to make a sweetener similar to maple syrup. Because it will bleed profusely from the wounds during this time, river birch is best pruned in late summer or fall instead of late winter or spring.

River birch should be planted in in full sun.

Because it is a large tree, river birch makes a wonderful specimen planting for larger properties. It can be used as a large focal point, to anchor the corner of a house on a large lot, or as a group of shade trees in a park or wide lawn. The high canopy casts light dappled shade when young, but provides medium shade when older. This species is a good choice for low spots and wet soils, such as near streams or ponds. Because the trees use a lot of water, many shade-loving plants do thrive when planted under river birches. Hostas are tolerant of the dry shade created by river birch.

River birch should be planted in full sun in moist soils. It does well on clay as that type of soil retains moisture well. Although it is prefers wet soils this species is only moderately resistant to flooding but tolerates dry summers once established. Trees planted on moist soils live longer than those on dry sites. It transplants easily

River birch is has few insect or disease problems. Bronze birch borer (Agrilus anxius) is a significant pest of most birches, but this species is the most resistant of the commonly grown birches. Iron chlorosis (leaves are chartreuse with darker veins) may be a problem on alkaline soils.

Several cultivars have been selected for ornamental use:

  • Dura Heat® (‘BNMTF’) is a more heat and drought tolerant form with a densely pyramidal habit. The exfoliating bark is pinkish-orange.
  • ‘Heritage’ is a popular, vigorous cultivar. It has heavily exfoliating bark, with layers of cinnamon, salmon and brown bark peeling back in big sheets to reveal creamy white inner bark. It looks best planted in multi-stemmed clumps.
  • ‘Little King’ (Fox Valley™) is a dwarf form (15-20 feet tall) with good peeling bark.

– Susan Mahr, University of Wisconsin – Madison


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River Birch Tree Facts

A river birch tree (Betula nigra) is an excellent specimen or accent plant because of its pyramidal form and delicate foliage. It usually has several trunks with papery peeling bark that reveals salmon or rust-colored patches. Although river birch trees are native to the freshwater shores and floodplains of the southern United States, they tolerate drier conditions than other species of birches

Description

River birches may grow up to 90 feet tall, but the average height is 40 to 70 feet, and 25 to 60 feet wide. The lower branches droop on older trees. Young trees have salmon- to rust-colored bark that matures to a silvery gray.

Varieties

‘Heritage’ river birch grows 50 feet tall with an oval canopy and lighter-colored bark than the species. ‘Fox Valley’ river birch has a dense oval to rounded form and grows 10 to 20 feet tall.

Culture

River birches grow best in moist soil in full sun in USDA zones 4 to 9. Their shallow root systems are sensitive to hot, dry soils, but are tolerant of flood conditions. They need acidic soil (pH 5 to 6.5) to prevent chlorosis (yellowing of leaves). Pruning cuts will bleed sap in the spring, so prune when the trees are dormant. River birches are resistant to bronze birch borers. Leafminers and leaf spots are minor problems on the trees.

Uses

River birches can be used as shade or street trees, where there is adequate irrigation. They are used in reclamation areas and to control soil erosion. Birds eat the seeds of river birches, while deer and other wildlife eat the leaves and twigs.

Medicinal Uses

An astringent made from the leaves and bark of river birches is used to treat eczema and other skin irritations, according to the University of Florida School of Forestry and Conservation article, “River Birch”. A tonic made from the leaves has been used for gout, kidney stones and rheumatism, while birch tea has been used to reduce fevers. (Never use river birch for these or any ailments, however, without consulting your doctor first.)

River Birch

River birch (Betula nigra) is a handsome tree that is native to the southeastern United States. It is considered the most widely adapted of all the birches, and hardy throughout South Carolina.

Mature river birch (Betula nigra) in a partially shady landscape.
Photo by Karen Russ, ©2015 HGIC, Clemson Extension

Mature Height/Spread

The river birch is a large deciduous tree, typically growing to 40 to 70 feet tall, but may grow as high as 90 feet. The average tree spread may be as much as 40 to 60 feet.

Growth Rate

This native birch grows at a medium to rapid rate (30 to 40 feet over a 20-year period). It tends to be short-lived (30 to 40 years) on many urban sites, possibly due to a shortage of water in restricted areas. They are a riparian tree species, and are primarily found in natural sites along the banks of stream and lakes, including areas that are prone to flooding. Birches situated in moist areas are longer-lived. Birches grow best in full sun to partial shade sites.

Ornamental Features

One of the most appealing features of the birch is the bark, which on larger, young branches and stems, is reddish to pinkish brown and peels off in papery strips. The exposed inner bark is gray-brown to cinnamon-brown to reddish brown. The bark of a mature birch is ridged and deepens to dark brown. This tree is handsome without leaves because of its graceful silhouette and exfoliating bark.

Separate male and female flowers are borne on the same tree; the male in the form of a catkin, and the female in cone-like clusters that fall from the tree and are blown for long distances by the wind. In the fall, the foliage turns pale yellow.

Landscape Use

The graceful elegance of the birch allows it to be used as a specimen or for naturalizing, and is best used in large areas. It transplants easily and is most effective when planted in groupings. A multi-trunk specimen is more handsome than single-trunk trees.

River birch (Betula nigra) trunk with exfoliating bark.
Photo by Karen Russ, ©2006 HGIC, Clemson Extension.

River birch should not be planted close to the house as a foundation plant because of root growth toward the foundation and the drop of leaves into gutters. It should not be planted in high-use areas such as driveways, walks and patios, as dead branches tend to be messy. Periodic pruning is required to remove these branches; this can be done at any time of year. However, pruning healthy branches should be done in the summer to provide adequate time for cuts to heal, because late season pruning will result in spring “bleeding”. This leaking of sap in the spring from recent wounds is not considered harmful, but may lead to concern that there is another problem.

River birch (Betula nigra) foliage.
Photo by Karen Russ, ©2015 HGIC, Clemson Extension

Although the river birch thrives in wet areas, it does not require excessive amounts of water. It tolerates fairly dry soils once it is established, but does grow best in moist fertile soils. Apply mulch to conserve soil moisture. It requires acidic soils, and may suffer from iron deficiency if pH levels are 6.5 or higher. This species requires full sun to partial shade and tolerates high temperatures. The species grows as far south as USDA Zone 9.

Problems

River birch may be troubled by various fungal leaf spot diseases, resulting in early leaf drop during rainy summers. However, they typically occur late in the season and most are not significantly detrimental.

Various leaf miners and aphids may infest it, but these problems are unimportant. One aphid causes the leaves to crinkle in the spring. It causes no lasting damage.

Fall webworms may produce webbing on the ends of limbs from June through the end of summer, and feed on foliage within the webbing. Prompt sprays of B.t. (Thuricide) or spinosad are the safer products to use for webworm control. If control is necessary, always spray in the early evening. River birch is not susceptible to invasion by the bronze birch borer, a common problem with other birches in the south.

Cultivars

  • Heritage® (‘Cully’ PP4409) – This is the most prominent of all the cultivars. It is faster-growing, has larger, glossier leaves and is less prone to leaf spot than the species. The bark exfoliates on younger trees and opens to a lighter, salmon-colored trunk. Grows 40 to 70 high by 40 to 60 feet wide
  • Dura-Heat® (‘BNMTF’ PPAF) – This is a smaller cultivar that grows to 30 to 40 feet tall. The exfoliating bark reveals inner bark that is creamy white. It is considered more heat and drought tolerant than the species.
  • ‘Summer Cascade’ (PP15,105) – This is a newer weeping form of river birch from NC, and has a unique pendulous growing habit. It may grow to 6 to 8 feet tall and 10 feet wide in 10 years.
  • Fox Valley® (‘Little King’) – This cultivar is a dwarf that may reach 8 to 10 feet tall and 9 to 12 feet wide in 10 years with good growing conditions.

‘Little King’ river birch (Betula nigra).
Photo by Karen Russ, ©2015 HGIC, Clemson Extension

  • City Slicker® (‘Whit XXV’ PP16573) – The exfoliating bark reveals creamy white inner bark. This cultivar from Oklahoma grows to 30 to 40 feet tall and 20 to 25 feet wide. May be more cold and heat tolerant than other cultivars.
  • x ‘Royal Frost’ – This birch has burgundy-red to purple foliage, followed by yellow-orange to red fall color. The exfoliating bark reveals white inner bark. Because this cultivar has much less heat tolerance, it should only be considered for use in the higher elevations of the upper counties of SC. A micro-climate of afternoon shade may be beneficial. It is a hybrid of B. populifolia ‘Whitespire’ and B. x ‘Crimson Frost’.
  • ‘Shiloh Splash’ (PP16362) – This is a variegated leaf cultivar of river birch with green foliage edged in creamy white. It grows to 30 feet tall and 15 feet wide. Growth rate is medium.

Note: Chemical control of diseases and insects on large trees is usually not feasible since adequate coverage of the foliage with a pesticide cannot be achieved.

Birch

Birch, any of about 40 species of short-lived ornamental and timber trees and shrubs constituting the genus Betula (family Betulaceae), distributed throughout cool regions of the Northern Hemisphere. Ivory birch (family Euphorbiaceae) and West Indian birch (family Burseraceae) are not true birches. The name bog birch is applied to a species of buckthorn, as well as to B. glandulosa.

European white birch (Betula pendula).G. Lord/Shostal Associates

A birch has smooth, resinous, varicoloured or white bark, marked by horizontal pores (lenticels), which usually peels horizontally in thin sheets, especially on young trees. On older trunks the thick, deeply furrowed bark breaks into irregular plates. Short, slender branches rise to a narrow pyramidal crown on a young tree; they become horizontal, often pendulous, on an older tree. The egg-shaped or triangular, usually pointed leaves have toothed margins; they are alternately arranged on the branchlets. They are usually bright green, turning yellow in autumn. The drooping male catkins flower before the leaves emerge; smaller, upright female catkins on the same tree develop in conelike clusters, which disintegrate at maturity, releasing tiny, one-seeded, winged nutlets.

  • Bark of the paper birch (Betula papyrifera).E.H. Ketchledge
  • Sweet birch (Betula lenta).Walter Chandoha

Gray birch, paper birch, river birch, sweet birch, yellow birch, and white birch are the best known; white birch is usually called silver birch in England, but the latter name is also sometimes given to paper birch and to yellow birch. The Japanese monarch birch (B. maximowicziana) is a valuable timber tree of Japan, especially in the plywood industry. Usually 30 metres (100 feet) high, with flaking gray or orange-gray bark, it has heart-shaped leaves about 15 centimetres (6 inches) long and is a hardy ornamental. The similar Japanese cherry birch (B. grossa) also produces useful timber.

  • Paper birch (Betula papyrifera), with white trunks, and sugar maple (Acer saccharum) trees.© John Anderson/iStock.com
  • Drawing of a white birch.Encyclopædia Britannica, Inc.

Water birch (B. occidentalis; B. fontinalis of some authorities), a shrubby tree native to moist sites along the western coast of North America, has nonpeeling, dark-red bark; it grows in clusters, with all stems rising from a common root system. It is sometimes called red birch, black birch, or mountain birch. Swamp birch (B. pumila), a similar but smaller shrub, is found on boggy sites; it may be erect or trailing and matted. Bog birch (B. glandulosa) of North America, also called tundra dwarf birch or resin birch, and dwarf birch, or dwarf Arctic birch (B. nana), native to most far northern areas of the world, are small alpine and tundra shrubs commonly known as ground birch. Both species have almost circular leaves, are food sources for birds and grazing animals, and may be planted as ornamentals. Several Chinese birches and the Japanese white birch (B. platyphylla japonica) are sometimes used ornamentally. A few natural hybrids between trees and shrubs of the genus Betula are cultivated as ornamentals in Europe and North America.

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Pale- to red-brown birchwood is used for flooring, furniture, cabinetry, interior finishing, vehicle parts, plywood, pulp, and turnery. The thin, water-impervious bark provided roofing, canoes, and shoes for North American Indians and early settlers. Birch oil and birch beer made from sap are obtained from the trees. Woodsmen rely on the ability of yellow and paper birch bark to burn even when wet.

Birches were among the first trees to become established after the glaciers receded. Hardy, quick growing, and relatively immune to disease and insect attack, they are valuable in reforestation, erosion control, and as protective cover, or nurse trees, for development of more permanent plants. Most require moist, sandy, and loamy soil; they are usually propagated by seeding or grafting. Many ornamental varieties are cultivated for their leaf colour, leaf shape, or growth habit.

All-season trees: River birch

The river birch, Betula nigra, also known as red birch, water birch or black birch, is native to the United States, with its geographical range encompassing almost the entire eastern half of the United States. Birches belong to the Betulaceae family. The genus Betula is birch and the species nigra means black. The species name generally tells something specific about a plant and for the river birch, it refers to the gray-brown, almost blackish bark.

When Prince Maximilian (Emperor of Mexico from 1864-1867) visited the United States, he declared the river birch the most beautiful of American trees. ‘Heritage,’ a cultivar of the river birch, was more recently selected as the 2002 Tree of the Year by the Society of Municipal Arborists.

The river birch is naturally found in thickets along rivers, streams and lakeshores. It is an excellent tree as its roots do a great job holding shorelines together, helping to prevent erosion. It is hardy, growing in zones 4-9. The river birch has a geographical range bigger than any birch in the states. It adapts well to hot climates and is the only birch found in southern states.

USDA-Zone Map USDA Plant Hardiness Zone Map. View larger image.

The river birch is popular in home landscapes and used in parks and commercial properties. I echo Prince Maximilian’s sentiments, as it is a personal favorite of mine as well. Tree experts also echo the praise for the river birch.

“Only the shaggy, brown river birch seems truly adapted to cities, holding its own with urban heat blasts and the deadly borer,” said Arthur Plotnik in “The Urban Tree Book.”

“‘Heritage’ river birch is an excellent selection with superior vigor, larger leaves and greater resistance to leaf spot,” said Michael Dirr in “Trees.”

River birch is known for its showy exfoliating bark all four seasons. Photo by Paul Wray, Iowa State University, Bugwood.org.

The river birch is a fast growing tree, reaching between 40 and 90 feet. With its graceful weeping branches, it make an excellent ornamental tree and adapts very well to most conditions. River birches like sun to full shade and the soil can be highly acidic to alkaline. It will grow in loam, clay or sand and is somewhat drought-tolerant. It will tolerate wet soils, but prefers moist growing conditions. River birches are also resistant to bronze birch borer; other pest may cause minimal damage. They are wind and ice tolerant, adding to their value in the landscape.

River birch can grow as high as 90 feet. Photo by Karan A. Rawlins, University of Georgia, Bugwood.org.

River birches are available in single stem or the more attractive multi-stem forms. They offer a nice, yellow fall color and showy exfoliating bark for all seasons. River birch peel in colorful flakes of brown, salmon, orange and lavender. As an added bonus, these will grow where white birches fail to thrive. The river birch also attracts wildlife, as birds eat its seeds and deer enjoy munching on twigs and foliage. Ruby-throated hummingbirds find the sap a tasty treat. Native Americans also found value in the tree’s sap as they boiled it to make a sweetener, much like maple syrup.

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