The American Elm That Survived Every Outbreak on the National Mall

Jefferson Elm (Ulmus americana 'Jefferson') comes with a remarkable pedigree: it was selected on the National Mall in Washington, D.C., after surviving every major Dutch elm disease outbreak that struck that famous boulevard, then released by the National Park Service after decades of observation. It's one of the most rigorously tested American elms for DED tolerance, and it carries the classic arching vase form back into the landscape with confidence. Hardy through USDA zone 4, it's a stately native. Whether you want to recreate a cathedral-canopy street in St. Paul, plant a heritage-quality shade tree in an Edina yard, or anchor a large Woodbury property, Jefferson is an elm with history.

Jefferson Elm Plant Details

Jefferson Elm Uses in Minnesota Landscapes

Heritage Vase-Shaped Shade Tree

Jefferson recreates the high, arching elm canopy that once defined American streets — including the National Mall itself. A single tree forms a broad, fountain-like vase and casts deep shade, making a distinguished centerpiece for a larger Twin Cities yard.

Boulevard and Cathedral-Canopy Streets

With its proven disease tolerance and classic form, Jefferson is an excellent boulevard tree, arching over a street to recreate the cathedral canopy that Dutch elm disease nearly erased.

Native Replacement Tree

Its native status and graceful form make Jefferson a meaningful replacement for ash trees lost to emerald ash borer, restoring a classic native canopy while supporting local wildlife.

Best Time to Plant Jefferson Elm in Minnesota

Plant in spring (late April–May, after the ground thaws) for a full growing season of root establishment, or in early fall (late August–early October) while the soil is still warm. Get it in the ground at least six weeks before the ground freezes — typically mid-November in the Twin Cities. Avoid mid-summer planting in heat and humidity, and never plant after mid-October or before spring thaw.

How to Plant Jefferson Elm

1. Dig wide, not deep — 2–3x the root ball width but only as deep as the ball is tall, so the root flare sits at or slightly above grade.
2. Check drainage — Jefferson tolerates wet soil, but if water pools and never drains, break through any clay hardpan or mound-plant slightly.
3. Backfill with the native soil mixed with 20–30% compost; don't build a pure-compost "container" the roots won't grow beyond.
4. Spacing — give a single specimen 35–50 feet of clearance from buildings and other large trees; space a boulevard row 45–55 feet apart for an arching canopy.
5. Build a 3–4 inch watering ring to direct water to the roots, then flatten it before winter so it doesn't trap ice.
6. Mulch with 2–3 inches of shredded bark or wood chips in a wide ring, kept 2 inches off the trunk. Never use gravel mulch in Minnesota — it doesn't insulate roots.

Watering Jefferson Elm in Minnesota

First Year Watering Schedule

Weeks 1–2: water deeply and slowly every 1–2 days. Month 1–2: every 3–4 days. Month 3–6: every 5–7 days during active growth, easing off when rainfall is adequate (the Twin Cities average about 3 inches a month from June through August). Stop watering 2–3 weeks before the ground freezes — usually late October — so the tree doesn't push tender growth heading into winter.

After Year One

An established Jefferson largely cares for itself, needing supplemental water mainly during extended droughts (two-plus weeks with no rain and temps above 80°F). Soak deeply to 8–12 inches every 7–14 days during dry spells and let natural rainfall do the rest.

Will Jefferson Elm survive a Minnesota winter? Yes. It's a native American elm rated to USDA zone 4 and is reliably hardy in Twin Cities winters. Wrap the young trunk the first winter to prevent sunscald and buck rub.

Is it resistant to Dutch elm disease? Yes — high tolerance. Jefferson was selected on the National Mall after surviving every major DED outbreak there, and released by the National Park Service after decades of testing. As with all elms it's strong tolerance rather than strict immunity.

What makes it special? Its history. Jefferson is a genuine American elm survivor from one of the most famous tree-lined spaces in the country, propagated so you can plant a piece of that resilience in your own landscape.

Is it native to Minnesota? Yes. American elm (Ulmus americana) is native to Minnesota and eastern North America. Jefferson restores that native with proven disease tolerance.

Does it handle clay and wet soil? Yes — very well. American elms naturally grow in floodplains and bottomlands, so Jefferson tolerates heavy clay-loam and wet, low-lying ground better than most large shade trees.

You May Also Like

• New Harmony Elm — a USDA-selected American elm with a refined, symmetrical vase form.
• Valley Forge Elm — the most DED-resistant native American elm, with a classic arching vase.
• Princeton American Elm — a classic DED-resistant native American elm.
• St. Croix Elm — a Minnesota-discovered survivor American elm with a grand vase form.
• American Sentry Linden — a uniform native linden ideal for boulevards.

How Many Jefferson Elm Do I Need?

Jefferson is a large canopy tree — one is a property centerpiece. Give a single specimen 35–50 feet of clearance from buildings and other big trees. For a cathedral-canopy boulevard or driveway allee, space trees 45–55 feet apart so the arching vases meet overhead — a 200-foot drive takes about 4–5 trees per side. Don't crowd it: the 30–60-foot mature spread needs real room.

Jefferson Elm Season-by-Season in Minnesota

• Spring: Small reddish flower clusters appear on bare branches in April, followed by papery samaras and fresh toothed leaves — elms are among the first natives to wake.
• Summer: The arching vase canopy casts deep, cathedral-like shade; dark-green foliage stays clean on this DED-tolerant survivor.
• Fall: Foliage turns a clear classic yellow — the historic color of America's elm-lined streets in October.
• Winter: The high, fountain-like branch architecture is unmistakable against the sky; strong wood sheds snow well.

At a Glance

✔ Minnesota Native   ✔ Deer-Resistant   ✔ Rain-Garden / Wet-Soil   ✔ Shade-Tolerant

Plant It With

• New Harmony Elm — a refined, symmetrical USDA-selected American elm to vary an elm boulevard.
• Valley Forge Elm — the most DED-resistant American elm, ideal alongside Jefferson for genetic diversity.
• St. Croix Elm — Minnesota's own survivor elm, discovered right here in the St. Croix Valley.
• American Sentry Linden — a uniform native linden to alternate with elms on a mixed boulevard.

Is Jefferson Elm Right for Your Yard?

Choose Jefferson if you have a larger lot, boulevard, or low wet spot in full sun and want a fast-growing, historic native canopy tree — it handles clay, floodplain-wet ground, and urban stress, and its DED tolerance is among the best-proven anywhere. It's not a fit for small yards or tight spots under wires: this tree wants to become 50–70 feet of arching canopy, so choose a compact tree like Japanese Tree Lilac where space is limited.