Autumn Treasure Ironwood
A Tough Native Shade Tree with Glowing Gold Fall Color
Autumn Treasure Ironwood (Ostrya virginiana 'JFS-KW5') is an improved selection of Minnesota's native ironwood, bred for a more uniform pyramidal-to-oval crown and brighter fall color than the wild species. Expect glowing golden-yellow to bronze foliage that lingers into late fall, on a tough, adaptable tree that handles sun or shade, clay or dry soil, and brutal Minnesota winters. Whether you need a dependable mid-size shade tree for a Plymouth backyard, a boulevard tree in Edina, or a native for a Woodbury woodland edge, Autumn Treasure delivers.
Autumn Treasure Ironwood Plant Details
| Attribute | Detail |
| Scientific Name | Ostrya virginiana 'JFS-KW5' (Autumn Treasure) |
| Common Names | Autumn Treasure Ironwood, American Hophornbeam, Ironwood |
| Mature Height | 25-35 feet |
| Mature Width | 18-25 feet |
| Growth Rate | Slow to moderate |
| Sun | Full sun to part shade (handles dappled light under canopy) |
| Water | Moderate; drought-tolerant once established |
| USDA Zones | 3-9 (Twin Cities is zone 4b-5a) |
| Soil | Highly adaptable; prefers well-drained loam, tolerates clay and dry sites |
| Foliage | Deciduous; bright golden-yellow to bronze fall color that lingers |
| Bark & Form | Fine-textured shreddy bark; uniform pyramidal-to-oval crown |
| Winter Hardiness | Reliable to -40F |
| Deer Resistance | Good; rarely a deer favorite |
| Native Status | Improved selection of a Minnesota native |
Autumn Treasure Ironwood Uses in Minnesota Landscapes
Reliable Mid-Size Shade and Lawn Tree
At 25 to 35 feet tall with a tidy oval crown, Autumn Treasure is right-sized for a typical Twin Cities yard — big enough to throw real shade, small enough not to overwhelm a lot. Its improved, uniform form makes it a far cleaner choice than wild ironwood for a front lawn or backyard focal tree in Edina, Plymouth, or Maple Grove, finishing the season with a glow of gold.
Tough Boulevard, Urban, and Dry Sites
Ironwood is famous for durability, and this selection keeps that toughness: once established it tolerates drought, clay, dry soil, and the compacted, reflected-heat conditions of streetside plantings. That makes it an excellent boulevard tree, parking-island tree, or pick for a hot, dry corner in Woodbury or Eden Prairie where softer trees decline.
Native and Shade-Tolerant Plantings
As an improved native, Autumn Treasure shines in naturalized and woodland settings. Ironwood is one of the most shade-tolerant trees we carry — it grows happily under taller oaks and maples — so it's ideal for layering a woodland edge or filling a shadier corner in Minneapolis and St. Paul where sun-loving trees thin out.
Best Time to Plant Autumn Treasure Ironwood in Minnesota
As a deciduous tree, Autumn Treasure can be planted across a wider window than evergreens. Spring (late April through May, once the ground has thawed) and early fall (September through mid-October) are both excellent, since the tree is leafless or hardening off and transplant stress is low. Spring planting allows a full season to establish; fall planting uses warm soil and cool air for strong rooting. Avoid the heat of midsummer when possible, and don't plant after mid-October, when frozen ground can heave new roots.
How to Plant Autumn Treasure Ironwood
- Dig wide, not deep. Make the hole 2 to 3 times the width of the root ball but no deeper — the root flare should sit slightly above grade. In heavy clay, go even wider.
- Check drainage. Fill the hole with water; if it pools for hours, loosen the surrounding clay or mound-plant a few inches high so roots aren't waterlogged.
- Backfill with amended soil. Mix native soil with 20 to 30 percent compost to loosen heavy clay and hold moisture during establishment.
- Set it at the right depth. Plant so the root flare is visible at the surface — never bury the trunk. Remove twine and fold back burlap on B&B stock.
- Build a water basin. Form a 3 to 4 inch soil ring around the base to direct water to the roots. Flatten it before winter so ice doesn't collect against the trunk.
- Mulch with bark. Spread 2 to 3 inches of shredded bark or wood chips in a wide ring, kept 2 inches off the trunk. Skip gravel mulch — it bakes roots and offers no winter insulation.
Watering Autumn Treasure Ironwood in Minnesota
First Year Watering Schedule
- Weeks 1–2: Deep soak every 1 to 2 days (15–25 minutes at a slow trickle).
- Month 1–2: Every 3 to 4 days, keeping the root zone evenly moist.
- Month 3–6: Every 5 to 7 days during active growth; more in heat, less when rain is steady.
- Stop watering 2 to 3 weeks before the ground freezes (late October in the metro) so the tree can harden off for winter.
After Year One
Once established, ironwood is genuinely drought-tolerant and rarely needs supplemental water. During prolonged dry spells (two-plus weeks without rain), give it a deep soak every 10 to 14 days; otherwise let Minnesota's rainfall do the work. Its toughness after establishment is a big part of why it's such a low-maintenance tree.
Will Autumn Treasure Ironwood survive a Minnesota winter?
Easily — it's hardy to roughly -40°F (USDA zone 3), well below anything the Twin Cities' zone 4b–5a delivers, and as a selection of a local native it's fully adapted to our winters. No special winter protection is needed once established.
Is it deer-resistant?
Generally yes. Ironwood is rarely a deer favorite, so Autumn Treasure holds up better than most young trees in high-pressure western suburbs like Minnetonka and Wayzata. A trunk guard is still wise the first winter or two to prevent buck rub, but heavy browse is uncommon.
How shade-tolerant is it?
Very. Ironwood naturally grows as an understory tree beneath taller hardwoods, so Autumn Treasure thrives in part shade where sun-demanding trees struggle. It also takes full sun, giving you flexibility to place it almost anywhere — a shady side yard or an open lawn.
What makes this better than a wild ironwood?
The 'Autumn Treasure' selection was chosen for a more uniform, symmetrical pyramidal-to-oval crown and brighter, more consistent golden-bronze fall color than seed-grown ironwood. You get all the legendary toughness of the native species in a cleaner, more landscape-ready form.
You May Also Like
- Ironwood — the straight native species, ideal for naturalized and woodland-edge plantings.
- Kentucky Coffeetree — a bold native shade tree with dramatic branch structure for larger spaces.
- Prairie Dream Birch — a hardy white-barked native birch for bright bark and bird value.
- Nannyberry Viburnum — a native small specimen tree with spring flowers, bird berries, and burgundy fall color.
How Many Autumn Treasure Ironwood Do I Need?
Autumn Treasure is a specimen shade tree, so most yards need just one as a lawn or boulevard tree. With a mature spread of 18–25 feet, space multiple trees 20–25 feet apart (trunk to trunk) for touching canopies, or 25–30 feet for distinct crowns. For a naturalized woodland edge, stagger a loose group of 3 at 15–20 feet apart and let the crowns knit together over time.
Autumn Treasure Ironwood Season-by-Season in Minnesota
- Spring: Fresh green leaves emerge along the tidy pyramidal crown, with subtle catkins that dangle before the foliage fills in.
- Summer: A dense canopy of crisp, birch-like dark green leaves casts cooling shade; hop-like papery seed clusters develop and feed songbirds.
- Fall: The headline act — glowing golden-yellow to bronze color that arrives reliably and lingers later than most shade trees.
- Winter: Fine-textured, shreddy gray-brown bark and an even oval silhouette give quiet structure; some bronze leaves often persist into early winter.
At a Glance
✔ Minnesota Native ✔ Deer-Resistant ✔ Drought-Tolerant ✔ Shade-Tolerant
Plant It With
- Ironwood (Hophornbeam) — the straight native species; pair them along a woodland edge for a layered native look.
- Kentucky Coffeetree — a bold-textured native canopy tree that towers behind ironwood's mid-size crown.
- Prairie Dream Birch — white native bark that pops against ironwood's gold fall color.
- Nannyberry Viburnum (Tree Form) — a native understory companion with spring bloom and bird berries.
Is Autumn Treasure Ironwood Right for Your Yard?
Pick Autumn Treasure if you want a tough, no-fuss mid-size shade tree that handles full sun or part shade, clay or dry soil, boulevard conditions, and deer pressure — all with dependable gold fall color. It's not a fit if you need fast shade: ironwood grows slowly to moderately, so choose a maple or elm where speed matters more than durability.