swamp mahogany (Eucalyptus robusta), photographi

Can I Grow Swamp Mahogany in Arkansas?

USDA Zones 6b-8b · Plant zone range 9-11

Unlikely — Zone Mismatch

swamp mahogany (zones 9-11) does not overlap with Arkansas's zone range (6b-8b). Growing outdoors is unlikely without significant protection.

One zone short — what would close it

Swamp Mahogany is hardy to zone 9, and the warmest ground in Arkansas is zone 8 — 1 zone short. Planted in open ground it will not survive a Arkansas winter. To grow it here, grow swamp mahogany in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.

A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →

Zone math from 9-11 (plant) against 6-8 (Arkansas). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.

Swamp Mahogany in Arkansas — the short answer

Swamp Mahogany in Arkansas: hardy in zones 9–11, full sun.

Plant zones
9-11
Rated hardy to zone 9 by Cal Poly SelecTree; USDA PLANTS Database lists 16 °F, converted to zone 9a, checked Oct 2026. Ceiling: our plant database.
Arkansas zones
6b-8b
USDA PHZM 2023
Frost window
Mar 2 - Mar 20 – Nov 15 - Nov 23
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
226 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free to start

Your yard isn't the whole zone.

Arkansas spans zones 6b-8b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score swamp mahogany against your parcel's actual hardiness, soil, and sun.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your parcel report in seconds — read in full free for your first 14 days

Arkansas is not one climate

Arkansas’s winter-low ladder runs across 75 counties, from zone 7 in Benton County to zone 8.5 in Union County. That is 15°F between the two counties’ average coldest night — the difference between swamp mahogany overwintering in the ground and coming under cover.

7 zonesBenton County8.5 zonesUnion County

The middle half of 75 counties runs 7.5–8 zones, with a median of 8 zones — a 1.5-zone span end to end.

Measured across 75 Arkansas counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where Swamp Mahogany Stands in Arkansas

Swamp Mahogany is rated for zones 9–11 — a cold floor USDA puts at 20 to 30°F. No Arkansas county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Arkansas winters, not about swamp mahogany.

Below the zone 9 floor

75 counties

3 of 75 shown

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Zone Comparison

Swamp Mahogany Needs

  • USDA Zones: 9-11
  • Sun: Full Sun
  • Mature size: 160 ft tall
  • Drought tolerance: Low

Arkansas Has

  • USDA Zones: 6b-8b
  • Last Hard Freeze (28°F): Mar 2 - Mar 20
  • First Hard Freeze (28°F): Nov 15 - Nov 23
  • Annual Rainfall: 44-56 inches
  • Common Soils: Silt loam, Sandy loam, Red clay

Plant Zone Range (zones 9-11)

9a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.5 – 7.5

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Swamp Mahogany in Arkansas

The frost window

Across Arkansas, the last spring hard freeze (28°F) clears between Mar 2 and Mar 20, and the first fall hard freeze lands between Nov 15 and Nov 23 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 240-day window you can count on — up to 266 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

Winter standing

Arkansas runs as cold as USDA zone 6, and no sourced winter-hardiness floor is on record for swamp mahogany, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether swamp mahogany is a permanent planting or a replant-every-spring crop for you turns on your own zone within Arkansas; check its hardiness range against that before treating it as long-lived ground.

Timing tuned to sub-state frost dates — Carroll County, not the statewide average.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Soil + Drainage Fit

Swamp Mahogany likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across Arkansas's silt loam and sandy loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 6.5 — worth knowing before you decide whether a Arkansas soil test result is a problem or just a number. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your Arkansas site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost.

Your land, not the state average

SSURGO maps about 33.9% of Arkansas as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Swamp Mahogany has low drought tolerance, so it is the fast-draining end that will cost you — your soil map unit, not the state average, is the real answer.

Check your parcel → Source: USDA NRCS SSURGO.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Arkansas soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Swamp Mahogany in Arkansas

Zone compatibility tells you about winter cold survival — but Arkansas growers also need to think about:

Hot, humid summers drive fungal and bacterial diseases

Heavy clay soils in parts of the Ozarks

Severe spring storms and hail risk

Growing swamp mahogany here specifically

Swamp Mahogany needs sharp drainage and sends deep roots; its growing tissue takes cold to about 30°F (FAO ECOCROP), but in Arkansas, about 33.9% of soils are poorly-drained (SSURGO), and standing water is what actually kills it.

Build swamp mahogany up on a coarse, free-draining mound so its crown never sit in saturated soil. How to handle it →

What to actually do about these — and the constraints that apply to every Arkansas grower, not just swamp mahogany — is covered on the Arkansas growing guide.

Timing shifts within Arkansas

Arkansas isn't one climate. In Carroll County, the last hard freeze (28°F) holds until about Mar 26 — roughly 16 days later than the recorded state median — so plant swamp mahogany to your county's window, not the statewide date.

County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.

Where in Arkansas Swamp Mahogany Is Zone-Hardy

Swamp Mahogany is rated for USDA zones 9–11. No Arkansas county reaches it. Even Union County, the state’s mildest winter at zone 8b, sits below the plant’s zone 9 floor — so in open ground this one needs winter protection here, or a container that comes under cover.

Across those 75 counties Arkansas’s winter-low ladder runs from zone 7a in Benton County to zone 8b in Union County — 1.5 USDA zones of spread, which is 15°F between the two counties’ average coldest night of the year. None of that range reaches the band swamp mahogany needs, so here the statewide answer really is the answer.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. Swamp Mahogany’s zone 9–11 band: Rated hardy to zone 9 by Cal Poly SelecTree; USDA PLANTS Database lists 16 °F, converted to zone 9a, checked Oct 2026. Ceiling: our plant database.. A parcel report resolves your address’s own zone and frost dates rather than its county’s.

Pollinator + Wildlife Value

Swamp Mahogany draws honeybees and native bees (high value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, swamp mahogany can only work that bloom inside Arkansas's frost window — roughly 254 days, opening after the last 28°F freeze (Mar 2 - Mar 20) and closing at the first (Nov 15 - Nov 23), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.

Good to Know Before You Plant Swamp Mahogany

Swamp Mahogany is listed as toxic to dogs, cats (leaves) at a moderate level. We haven't confirmed this against a published source yet. Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.

Arkansas Cooperative Extension

For Arkansas-specific cultivar recommendations, planting calendars, and pest pressure for swamp mahogany, the canonical source is University of Arkansas Cooperative Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Swamp Mahogany native to Arkansas?

No — the USDA PLANTS Database lists Swamp Mahogany as introduced rather than native in the Lower 48, so it is not part of Arkansas's native flora. It grows here as a garden plant; pairing it with a few Arkansas natives keeps local pollinators fed too.

Looking for plants that belong here? The Arkansas growing guide lists plants that USDA PLANTS records growing in Arkansas and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.

State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.

Common Questions About Growing Swamp Mahogany in Arkansas

When can I plant Swamp Mahogany in Arkansas?

Arkansas's last spring hard freeze (28°F) clears between Mar 2 and Mar 20, and the first fall hard freeze lands between Nov 15 and Nov 23 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Swamp Mahogany, so this page does not state whether it overwinters in Arkansas and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.

What hardiness zone is Swamp Mahogany grown in across Arkansas?

Arkansas spans USDA hardiness zones 6b-8b (USDA ARS PHZM 2023). Swamp Mahogany is listed for zones 9-11, which do not overlap them, so there is no zone in Arkansas where this page can call outdoor growing reliable. A parcel report resolves your own address's zone.

How many frost-free days does a typical Arkansas site have?

A typical Arkansas site sees ~254 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Swamp Mahogany needs 240+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Carroll, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Swamp Mahogany native to Arkansas?

No — the USDA PLANTS Database lists Swamp Mahogany as introduced rather than native in the Lower 48, so it is not part of Arkansas's native flora. It grows here as a garden plant; pairing it with a few Arkansas natives keeps local pollinators fed too.

How should I amend the soil for Swamp Mahogany in Arkansas?

Swamp Mahogany prefers pH 5.5-7.5 and poorly (saturated >50% of year), well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Arkansas soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Swamp Mahogany actually grow on my specific land in Arkansas?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores swamp mahogany against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free to start

Check your specific parcel in Arkansas

State-level data is a sketch. Your Growable Ground report scores swamp mahogany against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.

Three things about your lot that Arkansas swamp mahogany averages can't show:

Your soil pHYour frost-free days — Arkansas averages 254Your sun & shade

We read public map data around Arkansas — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Arkansas swamp mahogany average

Explore More

Explore Arkansas county by county

Arkansas carries 75 counties with their own USDA zone — a sample of the growing pages for swamp mahogany there:

Where else swamp mahogany grows

Swamp Mahogany's zone band crosses state lines — these are the states closest to Arkansas in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.

More to grow in Arkansas

Arkansas has a growing page for 1,012 plants — a rotating sample of the rest of the shelf.

Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →

Cite this dataset

Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643

Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643

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