Green Ash

Scientific Name: Fraxinus pennsylvanica Marshall

Green Ash

General Information
Usda Symbol	FRPE
Group	Dicot
Life Cycle	Perennial
Growth Habits	Tree
Native Locations	FRPE

Plant Guide

Alternate Names

Alternate names include: red ash, swamp ash, or water ash (Kennedy, 1990).

Uses

Livestock: Green ash stems are browsed by livestock (Johnson, 1971). Cattle utilize green ash habitats for shade, water, protection, and shelter during calving season (Gucker, 2005). Wildlife: Green ash seeds, stems, and foliage provide cover and food for several small animal species including rabbit. Both game and nongame bird species use this habitat for food, nesting sites and roosts (Gucker, 2005). Black birds, finches, grosbeaks, and cardinal feed on ash fruits (Twedt and Best, 2004). In a study by Hopkins (2004), the Coopers hawk and mountain bluebird nested only in green ash woods. Residential: Green ash is popular as a shade tree in residential areas because of its good form and adaptability to a wide range of sites. Windbreak: Green ash is used frequently in windbreaks and shelterbelt plantings. It is recommended to plant the tree in the central rows of multi-row windbreaks (Dickerson, 2002).

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g., threatened or endangered species, state noxious status, and wetland indicator values).

Description

General: Green ash is a native spreading, round topped tree which grows to a height of 70 feet or more. The deciduous leaves are pinnately compound, 8 to 12 inches long, with 5 to 9 leaflets. The leaflets are oblong, lustrous green on both sides or somewhat paler beneath. The twigs are pale gray along with brown bark. The fruit (samara), usually containing one seed, is light colored, 1 to 2 inches long and ¼ to 1/3 inch wide with a wing (Vines, 1960). Distribution: For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. Habitat: Green ash is found in areas with 15 to 60 inches of yearly precipitation. It is found growing naturally in bottomlands subject to frequent flooding or overflow (Stewart and Krajicek, 1973). Green ash is moderately tolerant to shade. Some woody species associated with green ash include box elder (Acer negunda), red maple (A. rubrum), pecan (Carya illinoensis), eastern cottonwood (Populus deltoides), black willow (Salix nigra), and American elm (Ulmus americana) (Kennedy, 1990).

Adaptation

Green ash grows on clay to sandy or silt soils (Stewart and Krajicek, 1973). It will also perform well when planted on neutral to alkaline medium to coarse textured upland sands and loams with good moisture (Kennedy, 1990). The species has a wide range of adaptation from eastern Montana, Great Plains, and eastern half of the United States (Vines, 1960).

Establishment

Soil analysis should be performed prior to planting to determine the necessary levels of nitrogen, phosphorus and potassium. Green ash has shown severe chlorosis when grown on a soil with a pH of 8.1 (Wright, 1965). Tests on a riverfront site in Mississippi have shown that green ash grew well on silt loam soils with pH ranging between 7.5 and 8.0 (Kennedy, 1990). Gilmore and Boggess (1963) noted that hardwoods such as green ash need better quality planting sites than pine (Pinus sp.).

Management

Green ash does not grow as fast as red maple (Acer rubrum) or elm; therefore it may be crowded out over time. Control the surrounding vegetative competition to maintain green ash (Dickerson, 2002). If this species is being used in a landscape, prune established trees every three to four years to maintain good form and structure (Colorado State University, 2011)

Pests and Potential Problems

Insects will feed on green ash. Oystershell scale (Lepidosaphes ulmi) can cause serious damage to seedlings and small trees in the Northeast. Carpenterworm (Prionoxystus robiniae) bores into large branches and trunks, allowing the entrance of fungi. The brown headed ash sawfly (Tomostethus multicinctus) and the black headed ash sawfly (Tethida barda) also cause damage. The ash borer (Podesesia syringae) damages the stems, thereby degrading lumber quality and contributing to decline in shelterbelt plantings (Solomon, 1975 and Wright, 1965). The emerald ash borer (Agrilus planipennis) has been detected in Michigan, Ohio, Pennsylvania and Canada. The beetle is responsible for the loss of millions of ash (Fraxinus sp.) trees. The beetle lays eggs between bark layers and crevices. After about one week, larvae hatch and begin to feed on an infected tree’s inner bark and phloem. The larvae change to prepupa and overwinter in the tree. The following spring, after pupation, adults emerge from holes they made in the tree. Symptoms include: branch dieback, branching on the tree trunk and vertical bark slits (USFS, 2004). A fungus (Mycosphaerella fraxinocola) creates a leaf spot which may lead to defoliation of young trees. Rust fungal infections can distort petioles and small twigs. Green ash in Texas and Oklahoma has shown susceptibility to Phymatrotrichum omnivorum which causes root rot (Wright, 1965). Older trees may be attacked by a fungus, Polyporus fraxinophilus, which attacks wood and turns it into a yellow pulp (Vines, 1960).

Seeds and Plant Production

Plant Production , Use soil moisture sensors to measure the soil moisture of Green Ash.

Plant Production

Green ash seeds begin to fall as soon as they ripen in the fall (Wright, 1965). Color can be an indicator of maturity. The samaras don’t change color from green to yellow or brown until the embryo is full grown (Bonner, 1974). If picked slightly green, keep the samaras from overheating (Kennedy, 1990). Seed clusters can be collected by hand or with pruners and seed hooks. Another method is to shake the limbs and collect the dried samaras on a sheet beneath the tree. Spread out the samaras for uniform seed drying. After drying, the samara clusters can be broken apart by hand, flailing, or running them through a brush machine (Bonner, 1974). Watch for damage to the samaras by the ash seed weevil. The greatest damage has been reported in seed harvested in the northeast and Great Plains, with less amounts in the south (Bonner, 2008). Remove the stems and trash by fanning or air screen cleaners. Cleaned seed of seed lots collected from the Midwest and Great Lakes region averaged 17,260 seeds per pound. In contrast, cleaned seed collected in Arkansas and Mississippi averaged 20,950 seeds per pound (Bonner, 2008). Dry the seeds down to between 7 and 10 percent moisture for storage. Seeds stored in sealed containers at this moisture level at 41° F kept their viability for seven years in a study by Barton (1945). Some green ash seeds may germinate the following spring, while others may be dormant for several years. Dormancy could be a combination of internal factors and seedcoat effects (Bonner, 2008). Germination of seeds collected from the northern part of the range includes a two-step process of warm stratification for 16 weeks at 68° F and then cold stratification for 16 weeks at 38° F. A one hour resoak in water should be completed weekly in the warm phase and every 2 weeks in the cold phase. Usually only cold stratification is needed for seed collected in the southern part of the range. Seed dormancy may also be affected by seed age. Older stored seeds appear more dormant than those that are freshly collected (Bonner, 1974). Green ash samaras. Steve Hurst @USDA-NRCS PLANTS database Seeds may be sown in the fall to stratify in the nursery bed. Sow at approximately 80 to 100 seed/m (25 to 30/ft) of row with a row spacing of 15 to 30 cm (6 to 12 in.) apart. Cover the rows with burlap or greenhouse shade cloth until germination begins. Densities of 110 to 130 seed/m2 (10 to 12ft2) are recommended to grow high quality seedlings (Kennedy, 1990). Nursery seedlings normally develop no side branches during the first year of growth. However, by the second year a small number may develop. Some young trees may have a single straight stem until they are 15 ft. (5m) tall (Wright, 1965). Mature height varies among green ash depending on the location. In the northern part of its range, green ash may reach heights of 50 to 60 feet and breast height diameters of 18 to 24 in. On quality sites in the southern part of its range, trees may grow up to 120 ft. in height and reach a breast height diameter of 24 to 30 in. (Putnam, Furnival, and McKnight, 1960). Cultivars, Improved, and Selected Materials (and area of origin) This is not a complete listing of green ash cultivars and releases. Please consult your local nursery for more information concerning releases adapted to your area. ‘Patmore’ was introduced by the Patmore Nursery, Brandon, Manitoba, Canada. This variety is pyramidal to oval shaped and is a seedless male tree. ‘Summit’ was introduced by the Summit Nursery, Stillwater, Minnesota. This male variety has an upright, narrow growth habit. ‘Marshall’s Seedless’ has a rounded growth form and less cold hardy than ‘Patmore’ or ‘Summit’ (Colorado State University, 2011). Dakota Centennial® Ash (F. Pennsylvania ‘Wahpeton’) is an upright, fast growing male tree introduced by North Dakota State University, Fargo, North Dakota. ‘Kindred’ is a male tree introduced by the late Ben Gilbertson, Kindred, North Dakota. ‘Bergeson’ is a patented variety introduced by Bergeson Nursery, Fertile, Minnesota. ‘Cardan’ is a seed strain cultivar released by the USDA-NRCS Plant Materials Center, Bismarck, North Dakota and USDA Northern Great Plains Research Laboratory, Mandan, North Dakota (North Dakota State University, 1999 and Dir, 1990). ‘Oahe’ and Prairie Harvest germplasm are releases by the USDA- NRCS Plant Materials Center, Bismarck, North Dakota.

Fact Sheet

Uses

Windbreak: Plant green ash in the central rows of multi-row windbreaks. It can also be used for single-row windbreaks, although loss of lower branches with age reduces effectiveness. Wildlife: Green ash is of moderate importance to wildlife. The winged seeds (samaras) are eaten by a number of birds and mammals including wild turkey and rodents. Whitetail and mule deer browse the twigs and foliage. Recreation and Beautification: Green ash is extensively planted as a shade and ornamental tree. New clones have increased its importance in the landscaping industry.

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

Description

Fraxinus pennsylvanica Marsh., green ash, is a deciduous, medium-sized tree with an open, irregular crown reaching about 50 feet in height. Native to eastern North America and is fairly common west to Wyoming and Colorado along plains watercourses at elevations below 6,000 feet. The tree is fast growing on moist bottomlands, and is extremely hardy to climatic extremes once established. Fruits are straw-colored, one-seeded, winged (samaras), 1 to 2 1/2 inches long, borne in dense branching clusters; flowers are inconspicuous, without petals, borne in dense clusters (panicles) near the ends of the twigs, male and female flowers on separate trees; leaves are opposite, pinnately compound, 4 to 6 inches long, 7 to 9 leaflets, narrowly elliptical, long-pointed, entire, bright green above, paler below; stem straight, bark thin with network of interlacing ridges, brown to dark gray, twigs smooth; roots are shallow, wide-spreading.

Adaptation and Distributoin

Robert H. Mohlenbrock USDA NRCS 1989 Midwestern Wetland Flora @USDA NRCS PLANTS Green ash is widely adapted to soils, moisture conditions and pH found east of the Rocky Mountains. The species will tolerate seasonal flooding, but is intolerant of shading from surrounding trees. Green ash is a fairly early successional tree on most sites. Green ash is distributed throughout the east and midwest of the United States. For a current distribution map, please consult the Plant Profile page for this species on the PLANTS Website.

Establishment

Green ash is comparatively easy to establish, and has been widely used for windbreaks in the plains and prairie states and provinces. The seedling will withstand weedy conditions, but at reduced growth rates.

Management

Green ash is not as rapid growing as red maple or elm, so it tends to be crowded out over time by its faster growing cohorts, Management to retain green ash includes control of competition, Deer will browse green ash seedlings so protective netting may be required where pressure is heavy, , Use soil moisture sensors to measure the soil moisture of Green Ash.

Plant Traits

Growth Requirements

Morphology/Physiology

Reproduction

Suitability/Use

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash

Green Ash