Mammoth Spring, Arkansas, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Expect cabbage, hazelnut, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Mammoth Spring, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Mammoth Spring lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Mammoth Spring — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Mammoth Spring — the short answer
Mammoth Spring, Arkansas: USDA zone 7a, about 223 days between hard freezes, across 827 acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~223
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 827 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7a is Mammoth Spring's average, not your lot's — a low corner or a tree line moves it. Against Mammoth Spring's 223-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mammoth Spring
Each reading below is measured for Mammoth Spring itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMammoth Spring runs about 223 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMammoth Spring sits in USDA hardiness zone 7a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Mammoth Spring is in
Mammoth Spring sits in the Ozark Highlands — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Mammoth Spring's own centroid rather than borrowed from Fulton County.
What Grows in Mammoth Spring
Every plant below cleared Mammoth Spring's own zone 7a and its 223-day season. Each card opens that plant's Arkansas profile. How we score.
Is it too late to plant in Mammoth Spring?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 5 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Mammoth Spring
Survey cells within 31 miles of Mammoth Spring checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 270 miles off. What to watch for.
What's on the federal record near Mammoth Spring
Closest first, within ~10 miles of Mammoth Spring. Listing isn't leaking, and distance isn't exposure.
- MAMMOTH SPRING SCHOOL DISTRICTUnderground Storage Tanks · 650 ft
- PARKER, VIRGLEUnderground Storage Tanks · 1300 ft
- MAMMOTH SPRING NAT FISH HATCHEUnderground Storage Tanks · 1800 ft
- KWIKSERVUnderground Storage Tanks · 0.5 mi
- HOCKER OIL CO GAS+ THAYERUnderground Storage Tanks · 0.6 mi
- MAMMOTH SPRING TEXACOUnderground Storage Tanks · 1.2 mi
- TERMINAL RAILROAD ASSN OF ST LOUISUnderground Storage Tanks · 1.7 mi
- THAYER FUEL CENTERUnderground Storage Tanks · 1.7 mi
- SPRING RIVER HATCHERYUnderground Storage Tanks · 1.8 mi
- WALMART #837Brownfields · 2.1 mi
- HELEN MOORE GROUnderground Storage Tanks · 2.2 mi
- NAPA AUTO PARTSUnderground Storage Tanks · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mammoth Spring's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Mammoth Spring.
Sources Checked
within ~10 miles of Mammoth Spring
Severity Distribution
within ~10 miles of Mammoth Spring
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mammoth Spring, Underground Storage Tanks runs higher than the national average — 29 sites within ~10 miles of Mammoth Spring. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Mammoth Spring
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Mammoth Spring average
Your land is one point inside Mammoth Spring
Everything above resolves to Mammoth Spring as a whole — one PHZM band and one 28°F frost record, read across 827 acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at city scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Mammoth Spring Average
Mammoth Spring Average
- ●USDA Zones 7a, averaged across Mammoth Spring
- ●One soil character for all of Mammoth Spring
- ●Frost dates read at Mammoth Spring's scale: Mar 27 to Nov 5
YOUR Parcel
- ✓Your exact zone, not Mammoth Spring's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mammoth Spring
Pull a site-specific report for your exact address in Mammoth Spring, Arkansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mammoth Spring averages can't show:
We read public map data around Mammoth Spring — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mammoth Spring average
How we know this about Mammoth Spring
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Mammoth Spring’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Mammoth Spring
When does frost risk typically end in Mammoth Spring?
The last hard freeze (28°F) in Mammoth Spring typically lands around Mar 27, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 17.
When is the first frost in Mammoth Spring?
The first hard freeze (28°F) in Mammoth Spring typically arrives around Nov 5, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 22, so the watching starts about Oct 6 — about 223 days after the spring freeze cleared.
How long is the growing season in Mammoth Spring?
Measured between 28°F hard freezes, Mammoth Spring sees about 223 frost-free days — roughly Mar 27 through Nov 5, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 17 to Oct 22, about 188 days.
Is the soil safe to grow vegetables in Mammoth Spring?
The federal record around Mammoth Spring is light — 38 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (29), the nearest Underground Storage Tanks record about 0.1 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Mammoth Spring?
From about Oct 6 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 5 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 5. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Mammoth Spring's scale — its 7a band and its 223-day season. Your yard writes its own version of Mammoth Spring's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Mammoth Spring’s own scale
7 of the readings below were taken at Mammoth Spring's own scale — its own ~223-day season between 28°F freezes, the 827 acres it covers and 38 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mammoth Spring's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Mammoth Spring's own 28°F hard-freeze dates, about Mar 27 and Nov 5 and the ~223-day span between themNOAA 1991–2020 Climate Normals
- 38 documented contamination sites on the federal record near Mammoth Spring, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Mammoth Spring's boundary and the 827 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~223-day seasonGrowable Ground crop-matching engine
- The ecoregion at Mammoth Spring's own centroid, the Ozark HighlandsUS EPA Level III Ecoregions
- Lanternfly survey cells around Mammoth Spring checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Mammoth Spring's 827 acres read through its county's SSURGO summaryfrom Fulton County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Fulton County
- The growing challenges every Arkansas grower plans around — written at state scale, so they stay on the state guidefrom Arkansas
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Fulton County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mammoth Spring's 827 acreswhy one lot differs from the next →
- Which side of Mammoth Spring you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 827 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Mammoth Spring-wide figureread your own land →
More in Arkansas
Growing region
Nearby growing guides