Kirby, Arkansas, sits in USDA hardiness zone 8a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, cabbage, fig, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Kirby, 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 Kirby 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 Kirby — soil, climate, flood, and parcel records. How we handle your address.
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Kirby — the short answer
Kirby, Arkansas: USDA zone 8a, about 240 days between hard freezes, across 9K acres of town.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~240
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 9K 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 8a is Kirby's average, not your lot's — a low corner or a tree line moves it. Against Kirby's 240-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Kirby
Each reading below is measured for Kirby itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredKirby runs about 240 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
MeasuredKirby sits in USDA hardiness zone 8a.
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 Kirby is in
Kirby sits in the Ouachita Mountains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Kirby's own centroid rather than borrowed from Pike County.
What Grows in Kirby
Every plant below cleared Kirby's own zone 8a and its 240-day season. Each card opens that plant's Arkansas profile. How we score.
Is it too late to plant in Kirby?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 13 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
What's on the federal record near Kirby
Closest first, within ~10 miles of Kirby. Listing isn't leaking, and distance isn't exposure.
- KIRBY KWIK STOPUnderground Storage Tanks · 2300 ft
- DUNLAP STOREUnderground Storage Tanks · 0.8 mi
- US ARMY CORPS ENG-NARROWS PWR PLTBrownfields · 2.5 mi
- KIRBY LANDINGUnderground Storage Tanks · 2.8 mi
- DAVID TAYLORUnderground Storage Tanks · 3.5 mi
- DUNLAPS STOREUnderground Storage Tanks · 3.5 mi
- KIRBY KWICK STOPUnderground Storage Tanks · 4.2 mi
- DAISY STATE PARKUnderground Storage Tanks · 4.5 mi
- KIRBY PUBLIC SCHOOLSUnderground Storage Tanks · 5.1 mi
- LAKESIDE GROCERYUnderground Storage Tanks · 5.1 mi
- Funderburk ProspectMining · 5.3 mi
- Cox ProspectMining · 5.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Kirby'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 Kirby.
Total Sites
113
within ~10 miles of Kirby
Risk Level
High
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Kirby
Severity Distribution
within ~10 miles of Kirby
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Kirby, Mining runs higher than the national average — 47 sites within ~10 miles of Kirby. That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Kirby
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 Kirby average
Your land is one point inside Kirby
Everything above resolves to Kirby as a whole — one PHZM band and one 28°F frost record, read across 9K 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 town 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 Kirby Average
Kirby Average
- ●USDA Zones 8a, averaged across Kirby
- ●One soil character for all of Kirby
- ●Frost dates read at Kirby's scale: Mar 18 to Nov 13
YOUR Parcel
- ✓Your exact zone, not Kirby's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Kirby
Pull a site-specific report for your exact address in Kirby, Arkansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Kirby averages can't show:
We read public map data around Kirby — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kirby average
How we know this about Kirby
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Kirby’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 town grain anywhere on this page — there is no town-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 Kirby
When does frost risk typically end in Kirby?
The last hard freeze (28°F) in Kirby typically lands around Mar 18, 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 8.
When is the first frost in Kirby?
The first hard freeze (28°F) in Kirby typically arrives around Nov 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 30, so the watching starts about Oct 14 — about 240 days after the spring freeze cleared.
How long is the growing season in Kirby?
Measured between 28°F hard freezes, Kirby sees about 240 frost-free days — roughly Mar 18 through Nov 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 8 to Oct 30, about 205 days.
Is the soil safe to grow vegetables in Kirby?
The federal record around Kirby runs heavier than most — 113 documented sites, mostly Underground Storage Tanks entries (56), the nearest Underground Storage Tanks record about 0.4 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Kirby?
From about Oct 14 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 13 (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 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Kirby's scale — its 8a band and its 240-day season. Your yard writes its own version of Kirby'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 Kirby’s own scale
6 of the readings below were taken at Kirby's own scale — its own ~240-day season between 28°F freezes, the 9,265 acres it covers and 113 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Kirby's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Kirby's own 28°F hard-freeze dates, about Mar 18 and Nov 13 and the ~240-day span between themNOAA 1991–2020 Climate Normals
- 113 documented contamination sites on the federal record near Kirby, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Kirby's boundary and the 9,265 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~240-day seasonGrowable Ground crop-matching engine
- The ecoregion at Kirby's own centroid, the Ouachita MountainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Kirby's 9,265 acres read through its county's SSURGO summaryfrom Pike County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Pike 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 Pike County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Kirby's 9,265 acreswhy one lot differs from the next →
- Which side of Kirby you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 9,265 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 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 Kirby-wide figureread your own land →
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