Emerald Ash Borer in Minnesota — Should You Treat or Remove?

Emerald ash borer (EAB) has reached every Twin Cities county. If you have an ash tree, you have a decision: treat indefinitely, or remove now.

The reality

• EAB kills 99%+ of untreated ash within 3–6 years of infestation.
• Treatment works, but it's forever — every 2–3 years for the life of the tree.
• Dead ash become brittle within 1–2 years and dangerous to remove (climbing them is unsafe; crane required = $$$).

Cost: treat vs. remove

Path	Year 1	Year 5	Year 15
Treat (trunk injection every 2 yr)	$200–$500	$600–$1,500	$1,800–$4,500
Remove + replant	$800–$2,500	+ $200 maintenance	$0
Wait until dead	$0	$1,500–$4,000 (dead removal)	$0

Removing while the tree is healthy is cheaper and safer than waiting. Dead ash is the most dangerous tree in the Twin Cities to remove.

When to treat

• Sentimental or shade-critical ash in good health (less than 30% canopy thinning).
• Tree is in a location where replacement would take decades (mature shade by patio, etc.).
• You're committed to forever-treatment.

When to remove

• Tree shows D-shaped exit holes, woodpecker damage, epicormic sprouting on trunk, or 30%+ canopy thinning.
• Multiple ash on the property — replanting now diversifies your canopy.
• Budget doesn't support indefinite treatment.

Identification

• Ash bark: diamond-pattern furrows on mature trees.
• Compound leaves: 5–11 leaflets opposite each other.
• EAB signs: D-shaped 1/8" exit holes, S-shaped tunneling under bark, woodpecker flecking ("blonding").

Replant recommendations

Don't replant ash. Good Twin Cities replacements:

• Hackberry — tough, fast, beautiful structure
• Kentucky coffeetree — drought-tolerant, no pests
• Bur oak (long term) — bulletproof but slow
• River birch — fast, attractive bark
• Hybrid elm (Princeton, Valley Forge) — Dutch-elm-resistant

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Have an ash on your property? Request a free assessment — we'll tell you honestly whether to treat or remove.