Green ash (Fraxinus pennsylvanica): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table.

At a glance

Item	What the source records
Scientific name	Fraxinus pennsylvanica Marsh., olive family
Other names	Red ash, swamp ash and water ash (Silvics)
Native status, USDA PLANTS	Native in Canada and in the lower 48 states
Size, Silvics	In the northern range 15 to 18 m (50 to 60 ft) tall and 46 to 61 cm (18 to 24 in) in diameter; on good southern sites up to 37 m (120 ft) and 61 to 76 cm (24 to 30 in)
Green weight of the wood, NRS-38	52 lb per cubic foot, without bark

Native range and where it is planted

The Silvics of North America handbook (Agriculture Handbook 654, 1990) calls green ash the most widely distributed of all the American ashes. It records a range from Cape Breton Island and Nova Scotia west to southeastern Alberta, south through central Montana and northeastern Wyoming to southeastern Texas, and east to northwestern Florida and Georgia. It describes the tree as naturally a moist bottom land or stream bank tree that is hardy to climatic extremes and has been widely planted in the Plains States and Canada. The handbook says the commercial supply is mostly in the South, and that the species is very popular as a residential shade tree for its form, its adaptability to a wide range of sites and its relative freedom from insects and diseases, in the words of the 1990 text.

Size and growth

Silvics gives the sizes in the table above. It adds that open-grown trees planted on a fertile soil in Pennsylvania reached 14 to 17 m (45 to 55 ft) tall and 20 to 30 cm (8 to 12 in) in diameter at age 21. In Georgia stands where green ash was dominant, average heights of sawtimber trees ranged from 24 m (78 ft) in a 27-year-old stand to 35 m (116 ft) in a 65-year-old stand. On most southern sites the handbook describes a clear, straight trunk for about half the total height, with forking, crooks and large branches above that point.

Flowers and seed

The handbook says green ash is dioecious, with separate male and female trees. The small flowers are usually inconspicuous and appear in spring with or just before the leaves, from March or April in Florida to late April or early May in the north of the range. Flowering starts when trees are 8 to 10 cm (3 to 4 in) in diameter and 6 to 8 m (20 to 25 ft) tall. Seeds start to fall as soon as they ripen and continue into winter, and most are dispersed by wind within short distances of the parent tree.

Roots

Silvics describes a root study in North Dakota in which roots extended 15 m (48 ft) sideways and 1.1 m (3.6 ft) downward, about equally spread through the upper 0.9 m (3 ft) of soil. It says excavations of other root systems found roots about 1 m (3.2 ft) deep in sandy and clay soils and 1.4 m (4.5 ft) deep along the edges of sloughs.

Wood

The Wood Handbook (FPL-GTR-282, 2021) treats green ash in its white ash group, with American white ash, blue ash and Oregon ash. It says the heartwood is brown and the sapwood light-colored or nearly white, and that the wood is heavy, strong, hard and stiff with high resistance to shock. Silvics says green ash is similar in property to white ash and is marketed together with it as white ash, though it is not as desirable for tool handles and baseball bats.

Wood Handbook figure	Green	At 12% moisture content
Specific gravity (Table 5-3b)	0.53	0.56
Modulus of rupture, lbf per square inch (Table 5-3b)	9,500	14,100
Side hardness, lbf (Table 5-3b)	870	1,200
Moisture content of green sapwood, percent (Table 4-1)	58	Not applicable

The green weight of the wood is in the NRS-38 table, the same figure used in the log weight calculator.

Pests and diseases the agencies name

Silvics (1990) says many insects feed at least occasionally on green ash and names the oystershell scale as one of the most serious. The printed page of the handbook ends its list there.

The Wood Handbook says that American white ash, green ash and blue ash, like black ash, are considered by the International Union for Conservation of Nature to be critically endangered because of the emerald ash borer. It adds that there is ongoing widespread harvesting of live and dead white ash in an effort to curtail the problem. The guide on emerald ash borer rules by country gives each agency's wording and the date on its page, and reporting a pest in the United States gives the office that takes sightings of regulated pests. For the ash disease regulated in the United Kingdom, see ash dieback rules. Who may apply pesticides is in pesticide licences by country.