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Water Ash Fraxinus pennsylvanica

Other Common Name(s):

Other plants called Water Ash:

Previously known as:

  • Fraxinus americana var. pennsylvanica
  • Fraxinus pennsylvanica var. lanceolata
Phonetic Spelling
FRAK-si-nus pen-sil-VAN-ih-kuh
Description

Green ash is a native, medium-sized, broadleaf deciduous tree that may grow 50 to 70 feet tall and 35 to 50 feet wide with a trunk 2 to 3.5 feet across. Young trees are pyramidal, but as the tree matures it becomes more rounded with an irregular crown. The bark is thick, gray-brown with shallow furrows and crisscrossing ridges which form diamond patterns. The leaves are opposite and pinnately compound with 7 to 9 leaflets. Small, light green to purple flowers, with no petals, mature in loose panicles in early spring. The female tree produces a single-winged, dry, flattened samara with a slender, thin seed cavity that matures in the fall. These can be numerous and can make a mess when they fall to the ground, but the seeds provide food for many kinds of wildlife. Male trees are usually preferred in the home landscape because they do not produce fruit.

Green ash is native to Central and Eastern Canada and the West Central and Eastern United States. Habitats include floodplains, mesic woodlands, riverbanks, swamps, and open fields. It is the most widely distributed of all the ash tree species. In North Carolina, this tree is often found in bottomlands and swamps, especially along brown water rivers and the low ground of Piedmont and lower mountains.

The genus name, Fraxinus, is the Latin name for ash trees. The specific epithet, pennsylvanica, means "of Pennsylvania." The red ash was formerly Fraxinus pennsylvanica, and the green ash was Fraximus pennsylvanica var. lanceolata. They are currently combined into the same species. The red ash and green ash trees are nearly identical; however, the green ash has nearly hairless leaves and twigs while the red ash has dense hairs on the leaves, stalks, and twigs. 

Green ash prefers full sun to light shade, moist, well-drained soils of clay or loam and will tolerate occasional flooding. It is probably the most adaptable of all the ashes and is deer resistant. It is tolerant of drought, wind, moderate salt, and alkaline soil. It transplants well and grows well in a variety of locations and soils. 

Planting new green ash trees are no longer recommended. The tree is very susceptible to infestation with the emerald ash borer. This borer will typically kill an ash tree within 3 to 5 years after infestation. It is very difficult to eradicate this pest which feeds under the bark and bores into wood.

Emerald ash borer is native to Asia and was first discovered in the U.S. in 2002. It has now spread to several additional states in the northeast and upper Midwest and is expected to continue spreading. This borer now constitutes a serious threat to all species of ash in North America.

Quick ID Hints:

  • grayish-brown bark with diamond-shaped ridges on older trees
  • pinnately compound leaves with 5 to 9 leaflets that are ovate to lance-elliptic
  • leaflet undersides are green ad margins are crenate to serrate from the mid-leaf to the tip
  • short-winged stalks on the leaflets 
  • leaf scar is semi-circular
  • flowers appear after the leaves emerge
  • female trees produce clusters of winged samaras

Insects, Diseases, and Other Pest Problems:  Green ash trees are generally susceptible to several insect problems including the Emerald ash borer, lilac borer, carpenter worm, oyster shell scale, leaf miners, fall webworms, ash sawflies, ash leaf curl aphids. Potential disease problems include fungal leaf spots, powdery mildew, rust, anthracnose, cankers, and ash yellows. General ash decline is also a concern. Brittle branches are susceptible to damage from high winds and snow/ice. See potential insect and disease problem factsheets to the left

VIDEO created by Ryan Contreras for “Landscape Plant Materials I:  Deciduous Hardwoods and Conifers or Landscape Plant Materials II:  Spring Flowering Trees and Shrubs” a plant identification course offered by the Department of Horticulture at Oregon State University

Profile Video:
See this plant in the following landscape:
Cultivars / Varieties:
  • 'Cimmaron'
    male tree, seedless, red to orange-red fall color
  • 'Johnson' or Leprechaun (trade name)
    dwarf, often grafted to a standard trunk
  • 'Marshall's Seedless'
    male, dark green foliage, 50 feet tall, 40 feet wide
  • 'Patmore'
    male, seedless, zone 2 hardy, good disease and insect resistance and handsome, uniform habit. Fall color is yellow.
  • 'Summit'
    male cultivar, vigorous, pyramidal tree that produces a strong central leader.
  • 'Urbanite'
    seedless, dense, pyramidal, bronze fall color
'Cimmaron', 'Johnson' or Leprechaun (trade name), 'Marshall's Seedless', 'Patmore', 'Summit', 'Urbanite'
Tags:
#deciduous#shade tree#drought tolerant#native tree#salt tolerant#winter interest#fall interest#rabbit resistant#windbreak#street tree#small mammals#wind tolerant#fire low flammability#NC native#beavers#porcupines#deer resistant#children's garden#playground plant#edible seeds#pollinator plant#Braham Arboretum#fantz#parks#larval host plant#deciduous tree#food source fall#food source herbage#Coastal FACW#Piedmont Mountains FACW#wet soils tolerant#bird friendly#food source hard mast fruit#mammals#butterfly friendly#Audubon#wind damage prone#fall color#insect problems#landscape plant sleuths course#wildlife friendly#cpp
 
Cultivars / Varieties:
  • 'Cimmaron'
    male tree, seedless, red to orange-red fall color
  • 'Johnson' or Leprechaun (trade name)
    dwarf, often grafted to a standard trunk
  • 'Marshall's Seedless'
    male, dark green foliage, 50 feet tall, 40 feet wide
  • 'Patmore'
    male, seedless, zone 2 hardy, good disease and insect resistance and handsome, uniform habit. Fall color is yellow.
  • 'Summit'
    male cultivar, vigorous, pyramidal tree that produces a strong central leader.
  • 'Urbanite'
    seedless, dense, pyramidal, bronze fall color
'Cimmaron', 'Johnson' or Leprechaun (trade name), 'Marshall's Seedless', 'Patmore', 'Summit', 'Urbanite'
Tags:
#deciduous#shade tree#drought tolerant#native tree#salt tolerant#winter interest#fall interest#rabbit resistant#windbreak#street tree#small mammals#wind tolerant#fire low flammability#NC native#beavers#porcupines#deer resistant#children's garden#playground plant#edible seeds#pollinator plant#Braham Arboretum#fantz#parks#larval host plant#deciduous tree#food source fall#food source herbage#Coastal FACW#Piedmont Mountains FACW#wet soils tolerant#bird friendly#food source hard mast fruit#mammals#butterfly friendly#Audubon#wind damage prone#fall color#insect problems#landscape plant sleuths course#wildlife friendly#cpp
  • Attributes:
    Genus:
    Fraxinus
    Species:
    pennsylvanica
    Family:
    Oleaceae
    Uses (Ethnobotany):
    Wood is heavy, hard, strong, and coarse-grained. The wood is used to make tool handles, oars, sports equipment, wood floors, and furniture.
    Life Cycle:
    Woody
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Central and Eastern Canada to West Central and Eastern US
    Distribution:
    Native: Canada--Alberta, Manitoba, Nova Scotia, Saskatchewan; United States--AL, AR, CO, CT, DE, DC, FL, GA, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, NE, NH, NJ, NY, NC, ND, OH, OK, PA, RI, SC, SD, TN, TX, UT, VT, VA, WV, WI, and WY. Introduced: Argentina, Austria, Belgium, Bulgaria, Central European Russia, Czechoslovakia, East European Russia, Germany, Hungary, Korea, Poland, Romania, South European Russia, Ukraine, United States--NM, and Yugoslavia.
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    The Green ash is a host plant for the Eastern Tiger Swallowtail butterfly and many moths.  The bark is eaten by rabbits, porcupines, and beavers.  Its foliage is browsed by white-tailed deer, seeds are eaten by birds, squirrels, and other small mammals.
    Play Value:
    Buffer
    Edible fruit
    Shade
    Wildlife Food Source
    Wind Break
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Fire in the landscape. Resistant to heat, drought, and soil compaction.
    Edibility:
    Bark can be used in cooking as a thickener for soups or mixed with grain in making bread.
    Dimensions:
    Height: 50 ft. 0 in. - 70 ft. 0 in.
    Width: 35 ft. 0 in. - 50 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Native Plant
    Perennial
    Tree
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Irregular
    Oval
    Pyramidal
    Spreading
    Growth Rate:
    Rapid
    Maintenance:
    Medium
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil Texture:
    Clay
    Loam (Silt)
    Sand
    Soil pH:
    Acid (<6.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Occasionally Wet
    Available Space To Plant:
    more than 60 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Green
    Display/Harvest Time:
    Fall
    Fruit Type:
    Samara
    Fruit Length:
    1-3 inches
    Fruit Width:
    < 1 inch
    Fruit Description:
    Fertilized female flowers give way to the fruit that is a single-winged, dry, flat samara. The wing extends less than half the body of the fruit, and there is a thin seed cavity. There are usually a large number of samara, and they appear narrow, 1 to 2 inches long, and 1/4 inch wide. Their color changes from green to tan as they mature. They hang in dangling clusters and are displayed on the tree from August to October. They can persist on the tree through the winter.
  • Flowers:
    Flower Color:
    Green
    Purple/Lavender
    Flower Inflorescence:
    Panicle
    Flower Bloom Time:
    Spring
    Flower Shape:
    Tubular
    Flower Size:
    < 1 inch
    Flower Description:
    The tree is primarily dioecious, which means it has separate male and female trees. The male flowers are tight clusters of small, apetalous, light green to purple blooms, and the female flowers are greenish blooms that appear in loose panicles. They appear on separate trees from April through May after the foliage emerges.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Leaf Value To Gardener:
    Showy
    Deciduous Leaf Fall Color:
    Brown/Copper
    Gold/Yellow
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Opposite
    Leaf Shape:
    Elliptical
    Lanceolate
    Ovate
    Leaf Margin:
    Crenate
    Entire
    Serrate
    Hairs Present:
    Yes
    Leaf Length:
    > 6 inches
    Leaf Width:
    > 6 inches
    Leaf Description:
    The leaves are 6 to 12 inches long, opposite, and pinnately compound with 5 to 9 entire leaflets. The leaflets are oval to lance-elliptic, 2.5 to 5 inches long, 1 to 1.75 inches wide, with a very short, less than 1/4 inch long winged stalk. The leaves are dark green and smooth on the upper surface, and the undersides are pale green with a silky pubescence. The margins may be crenate to serrate or entire. The pair of leaflets at the base of the leaf is smaller. The foliage turns yellow to bronze in fall, with the quality of the fall color often varying considerably from year to year.
  • Bark:
    Bark Color:
    Dark Brown
    Dark Gray
    Surface/Attachment:
    Furrowed
    Ridges
    Scaly
    Bark Plate Shape:
    Diamond
    Bark Description:
    The bark is a 1/2 inch thick or thicker, gray-brown with shallow furrows and corky ridges which form a diamond pattern. The bark on older trees may be scaly.
  • Stem:
    Stem Color:
    Brown/Copper
    Gray/Silver
    Green
    Stem Is Aromatic:
    No
    Stem Leaf Scar Shape:
    C-shaped, Cresent shaped
    Stem Lenticels:
    Conspicuous
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    The stem is stout, gray to greenish-brown, and may be smooth or pubescent with white lenticels. The leaf scars are semicircular to flat. The lateral buds sit on top of the leaf scar.
  • Landscape:
    Landscape Location:
    Lawn
    Meadow
    Recreational Play Area
    Woodland
    Landscape Theme:
    Butterfly Garden
    Children's Garden
    Native Garden
    Pollinator Garden
    Design Feature:
    Shade Tree
    Street Tree
    Attracts:
    Butterflies
    Moths
    Pollinators
    Small Mammals
    Songbirds
    Resistance To Challenges:
    Deer
    Drought
    Fire
    Pollution
    Rabbits
    Salt
    Wet Soil
    Wind
    Problems:
    Frequent Disease Problems
    Messy