Dutch Elm Disease Symptom Checker

Use this decision flow to narrow down what's wrong with your elm. This is not a substitute for a professional diagnosis — for any high-value or declining tree, contact a certified arborist or your state extension service. But it will help you know what questions to ask and what to look for.

Start here: peel back some bark

Cut a small (1–2 inch diameter) branch from a wilting section of your elm. Peel the bark back from the wood underneath and look at the freshly exposed wood.

What does the wood look like?

Chocolate brown to black streaks in the outer wood → Likely Dutch Elm Disease. See What Are the Symptoms of Dutch Elm Disease? for confirmation, then Who Should I Contact if I See Dutch Elm Disease? immediately. Time matters.

Olive green to dull greenish-brown streaks → Likely Verticillium wilt. Check whether nearby maples or other species also show wilting; Verticillium has a broad host range.

Wood looks completely normal — no streaks at all → Continue to the next question.

Sniff the inner bark

Scrape the inner surface of the cut bark and smell it.

Does it smell like wintergreen?

Yes → Almost certainly elm yellows, not Dutch Elm Disease. The wintergreen smell (methyl salicylate) is a near-pathognomonic sign of phytoplasma infection. Get lab confirmation and plan for tree removal — there's no effective field treatment.

No → Continue.

Look at individual leaves

Pull a symptomatic leaf from the tree and examine it.

What does the leaf look like?

Marginal browning with a yellow or reddish halo between the brown edge and the green center → Likely bacterial leaf scorch. This is a chronic disease — your tree may decline over years rather than weeks.

Black or dark brown spots and blotches, often along veins; leaves crinkled or distorted → Likely elm anthracnose. Mostly cosmetic — the tree should recover.

Cupped, twisted, strap-shaped, or rolled leaves → Likely herbicide injury. Look for recent spraying nearby.

Wilted then uniformly brown, mostly at the edges, often crispy → Possibly drought stress — especially if recent rainfall has been low. Try deep watering for 2–3 weeks before assuming the worst.

Leaves on individual branches wilted while other branches look fine → Combined with brown vascular streaking → Dutch Elm Disease. Without streaking → check the other categories above.

Look at the whole tree pattern

How are the symptoms distributed?

One or two branches dying ("flagging") while the rest of the tree looks healthy → Classic Dutch Elm Disease pattern. Confirm with the bark-peel test above.

The whole canopy is yellowing or wilting all at once → This is not typical Dutch Elm Disease. Consider:

Damage on one side of the tree, facing a road or neighboring property → Likely herbicide drift.

Damage on one side that faces full afternoon sun → Possibly sunscald or heat stress. Consider drought stress.

When to pay for lab confirmation

Get a wood sample lab-tested when:

  • The visual diagnosis is uncertain or could be multiple conditions
  • You're considering expensive treatment ($500–2000+) for a high-value tree
  • The diagnosis affects whether to remove the tree
  • This would be the first known DED case in your area
  • Insurance, legal, or municipal disputes depend on confirmation

State plant diagnostic labs (typically run by land-grant universities) test for $20–50 per sample. PCR tests can specifically identify Ophiostoma novo-ulmi, phytoplasmas (elm yellows), Xylella fastidiosa (BLS), and Verticillium dahliae.

For sample collection and shipping, see Who Should I Contact if I See Dutch Elm Disease?.

Quick reference: the matrix

For a side-by-side diagnostic table covering all six conditions in one view, see the Differential Diagnosis Guide.

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