Ash trees (Fraxinus): how to identify them

White ash vs green ash vs black ash

These are the three ashes most people meet in the eastern United States. The table draws on the Virginia Tech fact sheets for white ash, green ash and black ash, and on the USDA Forest Service's Silvics of North America.

The leaf-scar test is the one to learn. Pull a leaf off in late summer, or look at last year's scars in winter. If the scar is shaped like a U or a smile with the bud tucked inside, it is white ash. If the top of the scar is flat and the bud sits on it like a ball on a tee, it is green ash.

Range helps too. The Forest Service maps white ash from Cape Breton Island, Nova Scotia, to northern Florida, and west to eastern Minnesota and eastern Texas. Green ash is the most widely distributed American ash, reaching from Nova Scotia west to southeastern Alberta and south to southeastern Texas. Black ash ranges from western Newfoundland to southeastern Manitoba and eastern North Dakota, south only to Iowa, southern Indiana and West Virginia. A wet northern woodland with a slender ash in it points to black ash; the Forest Service records it as the only ash native to Newfoundland, also called basket ash because its wood splits easily into strips.

Ash look-alikes: hickory, walnut, boxelder and elm

People most often confuse ash with trees that share one of its traits, compound leaves or diamond-patterned bark. The quickest separations:

• Hickory and walnut have compound leaves too, but they are alternate: look along the twig and the leaves step up one at a time. Both bear nuts in husks, never winged seeds. See hickory and walnut for their own field marks.
• Boxelder is the one that catches careful people, because it is opposite and compound. Count the leaflets: boxelder has 3 to 5, coarsely toothed and often lobed like a maple leaf, on green to purplish twigs dusted with a whitish bloom. Its seeds come in V-shaped pairs.
• Elm shares the gray, diamond-furrowed bark, which is why "elm vs ash" is a common question in winter. Elm leaves are simple and alternate with a lopsided base, and elm buds sit slightly to one side of a slender, zigzag twig. Ash twigs are stout and opposite. A thin chip of elm bark shows alternating buff and reddish-brown layers, a test Virginia Tech gives for American elm.

Ash in winter

With the leaves gone, the opposite arrangement is still there in the twigs and buds. On a white or green ash, look for:

• Stout twigs with a large brown end bud flanked by two side buds.
• Leaf scars in opposite pairs, shaped as in the table above.
• Seed clusters still hanging on female trees: the Forest Service notes that white ash seeds fall between September and December, and Virginia Tech that green ash samaras disperse over winter.

Black ash is easy in winter if you see its buds: nearly black, with the first pair of side buds set some distance below the end bud. The winter tree identification guide covers bud and leaf-scar reading for other genera.

Emerald ash borer: what you will see on the tree

Emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle from Asia. USDA APHIS reports that it was first detected in North America in 2002 in southeast Michigan and had been found in 38 states and the District of Columbia when we read the page on October 21, 2026. A Forest Service pest alert states that in North America it infests all species of ash.

What a passer-by can see, according to those two USDA sources:

• D-shaped exit holes in the bark, where adults emerge in May and early June. The native redheaded ash borer, by contrast, leaves a round hole.
• S-shaped galleries under the bark, visible where bark has split or been peeled.
• Dead branches near the top of the crown, the crown thinning from the top down.
• Vertical splits in the bark.
• Sprouts on the trunk (epicormic branching).
• Woodpecker damage: woodpeckers strip the outer bark to reach the larvae, leaving pale patches.

The Forest Service warns that damage may not be apparent for up to three years after a tree is infested, and that drought, ash yellows and native borers can also stress ash. It also notes that the six-spotted green tiger beetle, often seen on hiking trails, is frequently mistaken for the borer. If you think you have found emerald ash borer, APHIS asks for a report through its website or at 1-866-322-4512, and both agencies ask people to buy firewood locally rather than move it. Treatment decisions belong with a certified arborist or your state forestry agency.

Tree Identifier's Diagnose tool can describe what it sees in a photo of a declining tree, but a report to APHIS or your state agency is what confirms the borer. If you are tracking particular ash trees, the app's Tree Map keeps each located identification so you can return to the same tree next season.

European ash (UK and Ireland)

In Britain and Ireland the ash is European ash, Fraxinus excelsior, which the Woodland Trust calls the third most common tree in Britain. It passes the same two checks as the American ashes: opposite branching and pinnately compound leaves, here with 3 to 6 opposite pairs of oval leaflets plus one at the tip. It grows to about 35 m (115 ft), its bark is pale brown to gray and fissures with age, and its winged seeds, called keys, appear in late summer and autumn.

The tell is the bud. European ash has black, velvety buds in opposite pairs, unlike the brown buds of white and green ash. Black ash in North America also has nearly black buds, but it grows in northern swamps on the other side of the Atlantic and has stalkless leaflets, so place settles that one.

European ash is also the tree behind the "ash dieback" in British news. Forest Research describes it as a disease caused by the fungus Hymenoscyphus fraxineus, of eastern Asian origin, first confirmed in the UK in February 2012 and now present in most of the UK and in Ireland. It notes blackened, wilting leaves and shoots, typically July to September, and dark diamond-shaped lesions on branches and trunks. For identification, that means a European ash in summer may have a thin crown and dead shoots; diagnosis and management belong with Forest Research guidance and a qualified arborist.

Why ash matters

White ash is the most common and useful native ash, according to the Forest Service: its wood is tough, strong and resistant to shock, and it has long been used for tool handles, oars and baseball bats. Wood duck, bobwhite, purple finch, pine grosbeak and fox squirrel eat its seeds. Green ash, hardy to climatic extremes, has been planted widely across the Plains and in towns, which is why so many street and yard trees are ashes. For the general method that works on any tree, see how to identify trees.