What USDA hardiness zone is St. Francis County, Arkansas?

Every ZIP code in St. Francis County, Arkansas is USDA hardiness zone 8a, from the USDA 2023 Plant Hardiness Zone Map.

When is the last spring frost in St. Francis County, Arkansas?

The median last spring freeze runs March 16 – March 23 across the 4 NOAA weather stations serving St. Francis County, Arkansas, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Arkansas

Planting zones in St. Francis County, Arkansas

Every ZIP code in this county is USDA zone 8a — so unlike most of the places people look up, there is one right answer here and it holds wherever you are in the county.

USDA zone 8a The same in all 9 ZIP codes

ZIP codes 9 9 have a NOAA station within range

Weather stations 4 NOAA 1991–2020 normals, across 635 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes St. Francis County, Arkansas as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact — enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.

St. Francis County does not have one planting answer

Its own weather stations disagree about 12 of the 32 crops in this table right now, so any single list would be wrong for part of the county. That is not a gap in the data — it is what the data says.

Shortest season: 231 days
WYNNE, AR US (USC00038052)
Longest season: 242 days
WEST MEMPHIS MUNI AP, AR US (USW00053959)

11 days of growing season separate those two stations, and both serve ZIP codes in St. Francis County. The ZIP lookup above answers for one address instead of averaging a place that has no average.

Why the hardiness zone does not settle this

A USDA zone is a winter-minimum statistic. It was never a growing-season one, and it does not behave like one: within a single zone the growing season runs a median 54 days wider at the 10th–90th percentile, and annual growing degree days vary by 2.02×.

The zones also overlap rather than stack — 30% of zone 6b freezes before the median zone 6a station. The zone tells you what survives your winter; the station tells you what finishes before your autumn.

The whole dataset behind that →

All 4 stations agreeAt least one station

Every one of the 4 NOAA stations serving this county counts March 23 – November 7 as growing season (229 days). Widening to any single station gives March 16 – November 11 (240 days).

Your freeze dates

Last spring freeze March 16 – March 23

First fall freeze November 7 – November 11

Across the 4 NOAA stations serving this county. These are medians — half of years freeze later than the date shown — so treat the later end of each range as the cautious one.

The growing season runs 231–242 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 89.1–90.8 °F in June–August. That is past the point where tomato and pepper pollen fails and cool-season greens bolt, so in this county heat decides as much as frost does. Summer rain over the same months runs 9.6–10.8" across those 4 stations, against the rough inch a week — about 13 inches over the same 92 days — that a vegetable garden is usually reckoned to want. The middle station covers about 81% of it, so expect to make up the rest. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 91 °F summer afternoon drying the soil faster than a cool one.

Every ZIP code in St. Francis County

Zones are published per ZIP code, not per county, so this is the exact answer rather than the county's average. The station column is the nearest one to that ZIP code's centroid and how far away it is — the same figure the tools use, shown here so you can see which ZIP codes are well covered and which are reaching.

ZIP code	USDA zone	Nearest NOAA station	Distance
72322	8a	Wynne, AR	20.7 km
72326	8a	Wynne, AR	18.4 km
72335	8a	Marianna 2 S, AR	28.4 km
72340	8a	Brinkley, AR	18.2 km
72346	8a	West Memphis Muni AP, AR	23.5 km
72359	8a	Wynne, AR	27.2 km
72372	8a	Brinkley, AR	25.9 km
72392	8a	Brinkley, AR	14.0 km
72394	8a	Wynne, AR	27.7 km

ZIP-code positions are area centroids, so a large rural ZIP code's listed distance is measured from the middle of its area rather than from any particular address in it.

When to start seeds in St. Francis County

Every date below is anchored on the last spring freeze at each station and reported as a range across all 4 of them, because no one station speaks for the county.

Crop	Job	When	Offset
🧅 Green Onions	Start indoors	January 19 – January 26	8 wk before
🌶️ Peppers	Start indoors	January 19 – January 26	8 wk before
🥦 Broccoli	Start indoors	February 2 – February 9	6 wk before
🥬 Cabbage	Start indoors	February 2 – February 9	6 wk before
🥬 Collards	Start indoors	February 2 – February 9	6 wk before
🥬 Kale	Start indoors	February 2 – February 9	6 wk before
🥬 Leaf Lettuce	Start indoors	February 2 – February 9	6 wk before
🫛 Peas	Direct sow	February 2 – February 9	6 wk before
🥬 Spinach	Direct sow	February 2 – February 9	6 wk before
🍠 Sweet Potato	Start indoors	February 2 – February 9	6 wk before
🍅 Tomatoes	Start indoors	February 2 – February 9	6 wk before
🥬 Bok Choy	Start indoors	February 9 – February 16	5 wk before
🥬 Kohlrabi	Start indoors	February 9 – February 16	5 wk before
🥬 Swiss Chard	Start indoors	February 9 – February 16	5 wk before
🥬 Arugula	Direct sow	February 16 – February 23	4 wk before
🥬 Baby Salad Greens	Direct sow	February 16 – February 23	4 wk before
🥕 Beets	Direct sow	February 16 – February 23	4 wk before
🧅 Green Onions	Direct sow	February 16 – February 23	4 wk before
🥬 Mustard Greens	Direct sow	February 16 – February 23	4 wk before
🌶️ Okra	Start indoors	February 16 – February 23	4 wk before
🌱 Radishes	Direct sow	February 16 – February 23	4 wk before
🥔 Turnips	Direct sow	February 16 – February 23	4 wk before
🥬 Cabbage	Set out	February 23 – March 2	3 wk before
🥕 Carrots	Direct sow	February 23 – March 2	3 wk before
🥬 Collards	Direct sow	February 23 – March 2	3 wk before
🥬 Collards	Set out	February 23 – March 2	3 wk before
🥒 Cucumbers	Start indoors	February 23 – March 2	3 wk before
🧅 Green Onions	Set out	February 23 – March 2	3 wk before
🥬 Kale	Direct sow	February 23 – March 2	3 wk before
🥬 Kale	Set out	February 23 – March 2	3 wk before
🥬 Kohlrabi	Direct sow	February 23 – March 2	3 wk before
🥬 Kohlrabi	Set out	February 23 – March 2	3 wk before
🥬 Leaf Lettuce	Direct sow	February 23 – March 2	3 wk before
🎃 Pumpkins	Start indoors	February 23 – March 2	3 wk before
🎃 Summer Squash	Start indoors	February 23 – March 2	3 wk before
🎃 Winter Squash	Start indoors	February 23 – March 2	3 wk before
🥒 Zucchini	Start indoors	February 23 – March 2	3 wk before
🥬 Bok Choy	Direct sow	March 2 – March 9	2 wk before
🥬 Bok Choy	Set out	March 2 – March 9	2 wk before
🥦 Broccoli	Set out	March 2 – March 9	2 wk before
🌿 Cilantro	Direct sow	March 2 – March 9	2 wk before
🥬 Leaf Lettuce	Set out	March 2 – March 9	2 wk before
🥬 Swiss Chard	Direct sow	March 2 – March 9	2 wk before
🥬 Swiss Chard	Set out	March 2 – March 9	2 wk before
🌿 Dill	Direct sow	March 9 – March 16	1 wk before
🫘 Bush Beans	Direct sow	March 23 – March 30	1 wk after
🥒 Cucumbers	Set out	March 23 – March 30	1 wk after
🎃 Pumpkins	Direct sow	March 23 – March 30	1 wk after
🎃 Pumpkins	Set out	March 23 – March 30	1 wk after
🎃 Summer Squash	Direct sow	March 23 – March 30	1 wk after
🎃 Summer Squash	Set out	March 23 – March 30	1 wk after
🌽 Sweet Corn	Direct sow	March 23 – March 30	1 wk after
🍅 Tomatoes	Set out	March 23 – March 30	1 wk after
🎃 Winter Squash	Direct sow	March 23 – March 30	1 wk after
🎃 Winter Squash	Set out	March 23 – March 30	1 wk after
🥒 Zucchini	Direct sow	March 23 – March 30	1 wk after
🥒 Zucchini	Set out	March 23 – March 30	1 wk after
🥒 Cucumbers	Direct sow	March 30 – April 6	2 wk after
🌶️ Okra	Direct sow	March 30 – April 6	2 wk after
🌶️ Okra	Set out	March 30 – April 6	2 wk after
🌶️ Peppers	Set out	March 30 – April 6	2 wk after
🫘 Southern Peas	Direct sow	March 30 – April 6	2 wk after
🍠 Sweet Potato	Set out	March 30 – April 6	2 wk after

Offsets are published guidance; the dates they land on are computed from measured NOAA normals. The seed-starting tool does this for your own ZIP code and counts the days.

What lives through a zone 8a winter

Of 74 perennial edibles, 57 come through a zone 8a winter — and 8 fail here for being too warm rather than too cold, needing more winter chill than this county gets or more heat than they tolerate. Among the ones that work: Apple, Aronia, Elderberry, Summer Raspberry, Asparagus, Horseradish, Rhubarb, Sunchoke.

Hardiness ranges are a judgement, published by growers rather than measured; the zone they are compared against is measured. On a warm-end verdict, check with your local extension service — a coastal zone 8 and an inland zone 8 are not the same summer.

Cautious — shortens the seasonMedian across stationsOptimistic

Last spring freeze: Plan to April 8 to be careful. Median March 16 – March 23 across 4 stations; February 28 is the optimistic end.
First fall freeze: Plan to October 24 to be careful. Median November 7 – November 11 across 4 stations; December 1 is the optimistic end.

NOAA publishes these as probabilities, not averages — the middle figure is a median, so half of years fall either side of it. The cautious end is the 10% tail: in roughly nine years in ten the freeze falls on the safe side of it.

The 4 stations behind these numbers

All 4 NOAA stations whose normals this page quotes, spanning about 57 km north to south. Every one is named with its identifier in the station list below — this page does not single one out, because no one station speaks for a whole county.

A relative sketch, not a map with a projection: longitude is adjusted for latitude so the shape is not stretched, and there is no basemap. For the one station nearest a specific address, with its real distance, use the ZIP lookup above.

These are the stations this county's ZIP codes actually cite as nearest — not a claim that each one sits inside its boundary, since a rural ZIP legitimately reaches over it. Every figure above comes from them, and each is named so you can check it.

Station	NOAA ID	Last spring freeze	First fall freeze	Season
Brinkley, AR	USC00030936	March 18	November 11	237 days
Marianna 2 S, AR	USC00034638	March 18	November 11	238 days
West Memphis Muni AP, AR	USW00053959	March 16	November 11	242 days
Wynne, AR	USC00038052	March 23	November 7	231 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Your own ZIP

Work out your own dates

This page describes a whole county. Every tool below answers for one ZIP code, which is the grain the underlying data is published at.

Other places to compare

St. Francis County sits in Arkansas. That page carries the whole state's zone spread, its metro areas, and every other county in it with a page here.

More of Arkansas

Counties with the same zones — 8a

Matched on the exact zone set, not a dominant zone, so the winter answer on these pages really is the same one as here.

Gear

If you want to act on this

Each link opens an Amazon search rather than a product we picked. We have not tested these and do not rank them — the search is the honest version, and you choose.

Shade clothSummer highs here average 91 °F, at or above the 90 °F point where lettuce and spinach bolt and tomato pollen fails.
Row cover and frost clothThe season here closes at the first fall freeze dated above — a cover buys back some of those days at the end.
MulchFor the perennials nearest their cold limit in zone 8a, where an insulated crown is what decides whether they come back.

As an Amazon Associate we earn from qualifying purchases. That costs you nothing extra, and it buys no influence over anything on this site: the dates come from NOAA normals and the zones from the USDA, and no product affects either.

Sources

Where these numbers come from

Hardiness zones are the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. Freeze dates and growing-season lengths are NOAA 1991–2020 Climate Normals, taken per station and cited above by name and NOAA ID.

County boundaries come from the Census ZCTA-to-county relation, which is what places each ZIP code — and which treats parishes, boroughs and census areas as county equivalents. No station is chosen to represent this county: every range above is taken across all of them and the count is stated, because picking one would be a judgement dressed as a measurement.