Arkansas
Planting zones in Clark 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.
Your ZIP code
Get the exact answer for your address
Everything above describes Clark 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.
Clark 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
- 223 days
SPARKMAN, AR US (USC00036768) - Longest season
- 234 days
DEGRAY LAKE SP, AR US (USC00031910)
11 days of growing season separate those two stations, and both serve ZIP codes in Clark 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.
All 4 stations agreeAt least one station
Every one of the 4 NOAA stations serving this county counts March 29 – November 4 as growing season (220 days). Widening to any single station gives March 20 – November 10 (235 days).
Your freeze dates
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 223–234 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 89.5–92.5 °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 11.1–13.2" 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 90% 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 Clark 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 |
|---|---|---|---|
| 71721 | 8a | Prescott 2 Nnw, AR | 18.5 km |
| 71728 | 8a | Arkadelphia 2 N, AR | 15.5 km |
| 71743 | 8a | Sparkman, AR | 25.2 km |
| 71772 | 8a | Prescott 2 Nnw, AR | 24.2 km |
| 71921 | 8a | Degray Lake SP, AR | 23.6 km |
| 71923 | 8a | Arkadelphia 2 N, AR | 6.1 km |
| 71962 | 8a | Prescott 2 Nnw, AR | 25.5 km |
| 71998 | 8a | Arkadelphia 2 N, AR | 2.0 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 Clark 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 23 – February 1 | 8 wk before |
| 🌶️ Peppers | Start indoors | January 23 – February 1 | 8 wk before |
| 🥦 Broccoli | Start indoors | February 6 – February 15 | 6 wk before |
| 🥬 Cabbage | Start indoors | February 6 – February 15 | 6 wk before |
| 🥬 Collards | Start indoors | February 6 – February 15 | 6 wk before |
| 🥬 Kale | Start indoors | February 6 – February 15 | 6 wk before |
| 🥬 Leaf Lettuce | Start indoors | February 6 – February 15 | 6 wk before |
| 🫛 Peas | Direct sow | February 6 – February 15 | 6 wk before |
| 🥬 Spinach | Direct sow | February 6 – February 15 | 6 wk before |
| 🍠 Sweet Potato | Start indoors | February 6 – February 15 | 6 wk before |
| 🍅 Tomatoes | Start indoors | February 6 – February 15 | 6 wk before |
| 🥬 Bok Choy | Start indoors | February 13 – February 22 | 5 wk before |
| 🥬 Kohlrabi | Start indoors | February 13 – February 22 | 5 wk before |
| 🥬 Swiss Chard | Start indoors | February 13 – February 22 | 5 wk before |
| 🥬 Arugula | Direct sow | February 20 – March 1 | 4 wk before |
| 🥬 Baby Salad Greens | Direct sow | February 20 – March 1 | 4 wk before |
| 🥕 Beets | Direct sow | February 20 – March 1 | 4 wk before |
| 🧅 Green Onions | Direct sow | February 20 – March 1 | 4 wk before |
| 🥬 Mustard Greens | Direct sow | February 20 – March 1 | 4 wk before |
| 🌶️ Okra | Start indoors | February 20 – March 1 | 4 wk before |
| 🌱 Radishes | Direct sow | February 20 – March 1 | 4 wk before |
| 🥔 Turnips | Direct sow | February 20 – March 1 | 4 wk before |
| 🥬 Cabbage | Set out | February 27 – March 8 | 3 wk before |
| 🥕 Carrots | Direct sow | February 27 – March 8 | 3 wk before |
| 🥬 Collards | Direct sow | February 27 – March 8 | 3 wk before |
| 🥬 Collards | Set out | February 27 – March 8 | 3 wk before |
| 🥒 Cucumbers | Start indoors | February 27 – March 8 | 3 wk before |
| 🧅 Green Onions | Set out | February 27 – March 8 | 3 wk before |
| 🥬 Kale | Direct sow | February 27 – March 8 | 3 wk before |
| 🥬 Kale | Set out | February 27 – March 8 | 3 wk before |
| 🥬 Kohlrabi | Direct sow | February 27 – March 8 | 3 wk before |
| 🥬 Kohlrabi | Set out | February 27 – March 8 | 3 wk before |
| 🥬 Leaf Lettuce | Direct sow | February 27 – March 8 | 3 wk before |
| 🎃 Pumpkins | Start indoors | February 27 – March 8 | 3 wk before |
| 🎃 Summer Squash | Start indoors | February 27 – March 8 | 3 wk before |
| 🎃 Winter Squash | Start indoors | February 27 – March 8 | 3 wk before |
| 🥒 Zucchini | Start indoors | February 27 – March 8 | 3 wk before |
| 🥬 Bok Choy | Direct sow | March 6 – March 15 | 2 wk before |
| 🥬 Bok Choy | Set out | March 6 – March 15 | 2 wk before |
| 🥦 Broccoli | Set out | March 6 – March 15 | 2 wk before |
| 🌿 Cilantro | Direct sow | March 6 – March 15 | 2 wk before |
| 🥬 Leaf Lettuce | Set out | March 6 – March 15 | 2 wk before |
| 🥬 Swiss Chard | Direct sow | March 6 – March 15 | 2 wk before |
| 🥬 Swiss Chard | Set out | March 6 – March 15 | 2 wk before |
| 🌿 Dill | Direct sow | March 13 – March 22 | 1 wk before |
| 🫘 Bush Beans | Direct sow | March 27 – April 5 | 1 wk after |
| 🥒 Cucumbers | Set out | March 27 – April 5 | 1 wk after |
| 🎃 Pumpkins | Direct sow | March 27 – April 5 | 1 wk after |
| 🎃 Pumpkins | Set out | March 27 – April 5 | 1 wk after |
| 🎃 Summer Squash | Direct sow | March 27 – April 5 | 1 wk after |
| 🎃 Summer Squash | Set out | March 27 – April 5 | 1 wk after |
| 🌽 Sweet Corn | Direct sow | March 27 – April 5 | 1 wk after |
| 🍅 Tomatoes | Set out | March 27 – April 5 | 1 wk after |
| 🎃 Winter Squash | Direct sow | March 27 – April 5 | 1 wk after |
| 🎃 Winter Squash | Set out | March 27 – April 5 | 1 wk after |
| 🥒 Zucchini | Direct sow | March 27 – April 5 | 1 wk after |
| 🥒 Zucchini | Set out | March 27 – April 5 | 1 wk after |
| 🥒 Cucumbers | Direct sow | April 3 – April 12 | 2 wk after |
| 🌶️ Okra | Direct sow | April 3 – April 12 | 2 wk after |
| 🌶️ Okra | Set out | April 3 – April 12 | 2 wk after |
| 🌶️ Peppers | Set out | April 3 – April 12 | 2 wk after |
| 🫘 Southern Peas | Direct sow | April 3 – April 12 | 2 wk after |
| 🍠 Sweet Potato | Set out | April 3 – April 12 | 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 18 to be careful. Median March 20 – March 29 across 4 stations; February 28 is the optimistic end.
- First fall freeze
- Plan to October 21 to be careful. Median November 4 – November 10 across 4 stations; November 28 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 48 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 |
|---|---|---|---|---|
| Arkadelphia 2 N, AR | USC00030220 | March 26 | November 4 | 225 days |
| Degray Lake SP, AR | USC00031910 | March 20 | November 10 | 234 days |
| Prescott 2 Nnw, AR | USC00035908 | March 29 | November 6 | 224 days |
| Sparkman, AR | USC00036768 | March 29 | November 4 | 223 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
Clark 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
- Desha County, AR 8b
- Logan County, AR 8a
- Pope County, AR 7b–8a
- Van Buren County, AR 7b
- Hempstead County, AR 8a–8b
- Pike County, AR 8a
- Carroll County, AR 7a–7b
- Boone County, AR 7a–7b
- White County, AR 8a
- Independence County, AR 7b–8a
- Izard County, AR 7a–7b
- Jefferson County, AR 8a–8b
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.