Swamp Mahogany is a tree, a long-term addition to the landscape. It's hardy across USDA zones 9 through 11. Its late winter flowers are a real draw for honeybees and native bees. It roots deep, which helps it reach moisture in a dry spell and open up tight soil as it establishes.
Swamp Mahogany — the short answer
Swamp Mahogany: grown in zones 9–11, full sun, pH 5.5–7.5.
- USDA zones
- 9–11
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Soil pH
- 5.5–7.5
- FAO ECOCROP
- Sun
- Full Sun
- Growable Ground Plant Database
- Frost-kill temp (growing season)
- 30.2°F
- FAO ECOCROP
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.
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Zone averages can't see the slope, soil, frost, and sun that decide whether swamp mahogany actually takes — and those shift from one yard to the next. Enter your address and we'll score swamp mahogany against your land's real conditions.
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What Swamp Mahogany is
Swamp Mahogany grows as a perennial and reaches around 160 feet at maturity. It blooms yellow in late winter.
How to grow Swamp Mahogany
Swamp Mahogany grows in USDA zones 9 through 11. Swamp Mahogany does best in full sun — at least 6 hours of direct sun a day — and soil from pH 5.5 to 7.5, on evenly moist to well-drained ground. It needs a growing season of at least 240 frost-free days, which is why climate matters as much as soil.
USDA Zones
9-11
USDA PHZM 2023
Soil pH
5.5 - 7.5
FAO ECOCROP
Sun
Full Sun
Growable Ground plant catalog
Drainage
poorly (saturated >50% of year), well (dry spells)
Growable Ground plant catalog
Frost Kill Temperature
30.2°F
Where cold starts killing growing tissue. Not a winter-survival floor — a dormant perennial takes far colder, which its hardiness zone answers.
FAO ECOCROP
Minimum Growing Temperature
41°F
Below this it stops growing rather than dies — a pace limit, not a survival limit.
FAO ECOCROP
Mature Height
160 ft
Growable Ground plant catalog
Frost-Free Days
240+
The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.
Growable Ground plant catalog
Plant it right
Set swamp mahogany in full sun with evenly moist to well-drained soil. Many fruit trees need a second variety nearby to pollinate — check before you plant just one.
Match the soil
Swamp Mahogany prefers pH 5.5 to 7.5 (FAO ECOCROP). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.
Water steadily
Keep the root zone evenly moist through establishment. A 2–3 inch mulch layer holds moisture without waterlogging.
Be patient, then harvest
Prune annually while the tree establishes; fruit trees reward patience with years of harvest. Local Extension guides publish per-cultivar bearing-age tables.
Where Swamp Mahogany thrives
Swamp Mahogany is hardy across USDA zones 9 through 11. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 9–11 spans average winter lows from 20°F to 50°F (USDA PHZM 2023). Across the 50 states and DC, that band covers none outright but splits 17 down the middle — and which side of that line your land sits on changes the answer.
Zones 9–11·Where Swamp Mahogany growsOpen map →
This map is derived from the USDA ARS / PRISM Plant Hardiness Zone Map (2023) and is not the official USDA Plant Hardiness Zone Map.
Where Swamp Mahogany stands, state by state
Swamp Mahogany is rated for zones 9–11 — a cold floor USDA puts at 20 to 30°F. Across the 50 states and DC, 0 sit fully inside that band, the line runs through 17 more, and 34 sit outside it — and inside every split state, the same line runs on at county grain.
The line runs through
17 states
- Alaska · zones 1a-9a
- California · zones 4b-11a
- Nevada · zones 4a-10a
3 of 17 shown
Swamp Mahogany’s band covers part of each of these states — which side of the line your county sits on changes the answer, and each state page draws it.
State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.
What grows around Swamp Mahogany
Growing guides for swamp mahogany
In rotation planning, swamp mahogany counts as a Other — beds recover best when other crops don’t follow each other in the same spot year over year. (Growable Ground derivation — crop-rotation group from botanical family)
Good to know
One caution for pet owners — swamp mahogany is toxic to dogs and cats (moderate severity). Keep it out of reach, and call ASPCA Animal Poison Control at (888) 426-4435 in an emergency. (Source: ASPCA.)
Swamp Mahogany is a standout pollinator plant — high value to bees and other pollinators.
Your land is one point inside Swamp Mahogany's range
This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.
See if Swamp Mahogany will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether swamp mahogany actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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How we know this about Swamp Mahogany
The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.
Grounded inUSDA PLANTS Database•USDA PHZM•ASPCA
Frequently asked questions
Can I grow Swamp Mahogany in my zone?
Swamp Mahogany grows in USDA hardiness zones 9 through 11 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
When should you plant Swamp Mahogany?
Set swamp mahogany out in early spring or fall while it's dormant, so the roots establish before the heat of summer. Your local last-frost date — which a Growable Ground report pulls for your exact address — sets the precise window.
How much sun does Swamp Mahogany need?
Swamp Mahogany needs full sun — a spot that catches at least 6 hours of direct summer sun a day. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.
What soil does Swamp Mahogany need?
Swamp Mahogany prefers soil pH 5.5 to 7.5, on evenly moist to well-drained ground (FAO ECOCROP). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Swamp Mahogany attract pollinators?
Yes — swamp mahogany's flowers are a strong nectar and pollen source for honeybees and native bees.
Is Swamp Mahogany safe for pets?
Swamp Mahogany is toxic to pets (dogs,cats) with moderate severity. Keep it out of reach, and call ASPCA Animal Poison Control at (888) 426-4435 in an emergency. (Source: ASPCA.)
Keep exploring Swamp Mahogany
Swamp Mahogany state by state
Every state swamp mahogany's zone reaches — 7 link straight to that state's swamp mahogany growing page; the rest open the state's full growing guide.