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Place guide

Planting zones in Fort Smith, AR-OK

This metro spans USDA zones 7b to 8a, so there is no single zone for Fort Smith, AR-OK and anyone who gives you one is rounding. 55% of its ZIP codes are zone 7b; the rest are not.

USDA zones 7b–8a 2 zones across 31 ZIP codes
ZIP codes 31 31 have a NOAA station within range
Weather stations 5 NOAA 1991–2020 normals, across 1,800 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Fort Smith, AR-OK as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact β€” enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.

Works for all 40,502 US ZIP codes. Freeze dates need a NOAA station within 100 km; where there is none, the page says so rather than estimating one.

The growing season in Fort Smith, AR-OK is closing

Nothing in the 32-crop table still has time to mature here. The first fall freeze normally arrives October 28 – November 7 across the 5 NOAA stations serving this metro area .

Your next season already has a date

The first job of it is πŸ§… Green Onions, start indoors, around January 28 – February 12 β€” counted back from a last spring freeze of March 25 – April 9 here.

Every spring date for your ZIP β†’

These are ranges across the whole metro area. The ZIP lookup above gives the dates from your own nearest station instead.

Growing season across Fort Smith, AR-OK A one-year bar. Every one of the 5 NOAA stations serving this metro area counts April 9 to October 28 as growing season, 202 days. At least one counts March 25 to November 7, 227 days. The same figures are written out below this chart. JFMAMJJASONDApril 9October 28

All 5 stations agreeAt least one station

Every one of the 5 NOAA stations serving this metro area counts April 9 – October 28 as growing season (202 days). Widening to any single station gives March 25 – November 7 (227 days).

That is a 25-day difference inside one metro area β€” which is why this page gives ranges rather than a single planting date. The ZIP lookup above resolves it to one station.

Which zone you are in depends where you are

Fort Smith, AR-OK covers 2 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it β€” which is fine for the 55% in zone 7b and wrong for the other 45%. Here is the actual split.

Zone ZIP codes Share  
7b 17 55%
8a 14 45%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

Last spring freeze March 25 – April 9
First fall freeze October 28 – November 7

Those are the earliest and latest medians among the 5 stations serving this metro β€” not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.

The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things β€” a zone is the average annual coldest night, a freeze date is when the season turns β€” and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.

Your growing season

NOAA publishes a growing-season length for each station, and across the 5 stations serving Fort Smith, AR-OK it runs 201–224 days . That figure is published, not computed from the two freeze dates β€” subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 89–93 Β°F , at or above the 90 Β°F point where cool-season crops bolt and tomato and pepper pollen fails β€” so midsummer sowings of lettuce and its relatives are worth holding here. Summer rain over the same months runs 11.2–12.7" across those 5 stations, against the rough inch a week β€” about 13 inches over the same 92 days β€” that a vegetable garden is usually reckoned to want. The middle station covers about 91% 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 Β°F summer afternoon drying the soil faster than a cool one.

When to start seeds in Fort Smith, AR-OK

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 5 stations β€” the earliest and latest that job falls anywhere in the metro β€” because no one station speaks for the whole area.

Crop Job When Offset
Green Onions Start indoors January 28 – February 12 8 weeks before
Peppers Start indoors January 28 – February 12 8 weeks before
Broccoli Start indoors February 11 – February 26 6 weeks before
Cabbage Start indoors February 11 – February 26 6 weeks before
Collards Start indoors February 11 – February 26 6 weeks before
Kale Start indoors February 11 – February 26 6 weeks before
Leaf Lettuce Start indoors February 11 – February 26 6 weeks before
Peas Direct sow February 11 – February 26 6 weeks before
Spinach Direct sow February 11 – February 26 6 weeks before
Sweet Potato Start indoors February 11 – February 26 6 weeks before
Tomatoes Start indoors February 11 – February 26 6 weeks before
Bok Choy Start indoors February 18 – March 5 5 weeks before
Kohlrabi Start indoors February 18 – March 5 5 weeks before
Swiss Chard Start indoors February 18 – March 5 5 weeks before
Arugula Direct sow February 25 – March 12 4 weeks before
Baby Salad Greens Direct sow February 25 – March 12 4 weeks before
Beets Direct sow February 25 – March 12 4 weeks before
Green Onions Direct sow February 25 – March 12 4 weeks before
Mustard Greens Direct sow February 25 – March 12 4 weeks before
Okra Start indoors February 25 – March 12 4 weeks before
Radishes Direct sow February 25 – March 12 4 weeks before
Turnips Direct sow February 25 – March 12 4 weeks before
Cabbage Set out March 4 – March 19 3 weeks before
Carrots Direct sow March 4 – March 19 3 weeks before
Collards Direct sow March 4 – March 19 3 weeks before
Collards Set out March 4 – March 19 3 weeks before
Cucumbers Start indoors March 4 – March 19 3 weeks before
Green Onions Set out March 4 – March 19 3 weeks before
Kale Direct sow March 4 – March 19 3 weeks before
Kale Set out March 4 – March 19 3 weeks before
Kohlrabi Direct sow March 4 – March 19 3 weeks before
Kohlrabi Set out March 4 – March 19 3 weeks before
Leaf Lettuce Direct sow March 4 – March 19 3 weeks before
Pumpkins Start indoors March 4 – March 19 3 weeks before
Summer Squash Start indoors March 4 – March 19 3 weeks before
Winter Squash Start indoors March 4 – March 19 3 weeks before
Zucchini Start indoors March 4 – March 19 3 weeks before
Bok Choy Direct sow March 11 – March 26 2 weeks before
Bok Choy Set out March 11 – March 26 2 weeks before
Broccoli Set out March 11 – March 26 2 weeks before
Cilantro Direct sow March 11 – March 26 2 weeks before
Leaf Lettuce Set out March 11 – March 26 2 weeks before
Swiss Chard Direct sow March 11 – March 26 2 weeks before
Swiss Chard Set out March 11 – March 26 2 weeks before
Dill Direct sow March 18 – April 2 1 week before
Bush Beans Direct sow April 1 – April 16 1 week after
Cucumbers Set out April 1 – April 16 1 week after
Pumpkins Direct sow April 1 – April 16 1 week after
Pumpkins Set out April 1 – April 16 1 week after
Summer Squash Direct sow April 1 – April 16 1 week after
Summer Squash Set out April 1 – April 16 1 week after
Sweet Corn Direct sow April 1 – April 16 1 week after
Tomatoes Set out April 1 – April 16 1 week after
Winter Squash Direct sow April 1 – April 16 1 week after
Winter Squash Set out April 1 – April 16 1 week after
Zucchini Direct sow April 1 – April 16 1 week after
Zucchini Set out April 1 – April 16 1 week after
Cucumbers Direct sow April 8 – April 23 2 weeks after
Okra Direct sow April 8 – April 23 2 weeks after
Okra Set out April 8 – April 23 2 weeks after
Peppers Set out April 8 – April 23 2 weeks after
Southern Peas Direct sow April 8 – April 23 2 weeks after
Sweet Potato Set out April 8 – April 23 2 weeks after

The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.

What survives the winter changes across Fort Smith, AR-OK

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 57 come through the winter in zone 8a and only 56 in zone 7b. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
7b 17 56 of 74 3
8a 14 57 of 74 8

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 Β°F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

How certain the freeze dates are in Fort Smith, AR-OK Two rows. Each runs from the cautious date, which shortens the growing season, to the optimistic one. The median dates sit between them. Every figure is repeated in the text below this chart. JFMAMJJASONDLast spring freezeFirst fall freeze

Cautious β€” shortens the seasonMedian across stationsOptimistic

Last spring freeze
Plan to April 28 to be careful. Median March 25 – April 9 across 5 stations; March 4 is the optimistic end.
First fall freeze
Plan to October 13 to be careful. Median October 28 – November 7 across 5 stations; November 26 is the optimistic end.

NOAA publishes these as probabilities, not averages β€” 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 5 stations behind these numbers

The 5 NOAA stations serving Fort Smith, AR-OK A relative sketch of where the stations sit, about 81 kilometres north to south. Each is named with its NOAA identifier in the station list on this page, which carries the same information as text. FT SMITH RGNL AP, AR US (USW00013964)MOUNTAINBURG 2 NE, AR US (USC00035018)SALLISAW 2 NW, OK US (USC00347862)WALDRON, AR US (USC00037488)WEBBERS FALLS 5 WSW, OK US (USC00349445) ~81 km north to south

All 5 NOAA stations whose normals this page quotes, spanning about 81 km north to south. Every one is named with its identifier in the station list below β€” this page does not single one out, because no one station speaks for a whole metro area.

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.

Every figure above comes from these, and each is named so you can check it. Which station serves a given ZIP code, and how far away it is, varies across the metro β€” the table below gives it per ZIP code rather than this page averaging it.

Station NOAA ID Last spring freeze First fall freeze Season
Ft Smith Rgnl AP, AR USW00013964 March 25 November 6 224 days
Mountainburg 2 NE, AR USC00035018 April 9 October 28 201 days
Sallisaw 2 NW, OK USC00347862 March 30 November 7 223 days
Waldron, AR USC00037488 April 8 October 28 203 days
Webbers Falls 5 Wsw, OK USC00349445 April 6 October 30 206 days

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

Every ZIP code in Fort Smith, AR-OK

Zones are published per ZIP code, not per metro area, so this is the exact answer rather than the metro area's average. The station column is the nearest one to that ZIP code's centroid and how far away it is β€” 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
72901 8a Ft Smith Rgnl AP, AR 5.9 km
72903 8a Ft Smith Rgnl AP, AR 2.4 km
72904 8a Ft Smith Rgnl AP, AR 9.3 km
72905 8a Ft Smith Rgnl AP, AR 13.4 km
72908 8a Ft Smith Rgnl AP, AR 4.9 km
72916 8a Ft Smith Rgnl AP, AR 6.9 km
72921 8a Mountainburg 2 NE, AR 21.0 km
72923 8a Ft Smith Rgnl AP, AR 7.2 km
72932 7b Mountainburg 2 NE, AR 20.7 km
72934 7b Mountainburg 2 NE, AR 12.5 km
72935 8a Mountainburg 2 NE, AR 17.4 km
72936 8a Ft Smith Rgnl AP, AR 20.6 km
72937 7b Ft Smith Rgnl AP, AR 22.2 km
72938 7b Waldron, AR 27.4 km
72940 7b Ft Smith Rgnl AP, AR 25.3 km
72941 8a Ft Smith Rgnl AP, AR 18.0 km
72944 7b Waldron, AR 18.6 km
72945 7b Ft Smith Rgnl AP, AR 26.0 km
72946 7b Mountainburg 2 NE, AR 1.7 km
72948 7b Mountainburg 2 NE, AR 22.4 km
72952 7b Mountainburg 2 NE, AR 16.1 km
72955 7b Mountainburg 2 NE, AR 25.9 km
72956 8a Ft Smith Rgnl AP, AR 15.2 km
74435 7b Webbers Falls 5 Wsw, OK 15.9 km
74936 7b Sallisaw 2 NW, OK 9.8 km
74945 7b Sallisaw 2 NW, OK 14.1 km
74946 8a Ft Smith Rgnl AP, AR 10.8 km
74948 7b Sallisaw 2 NW, OK 21.4 km
74954 8a Ft Smith Rgnl AP, AR 14.6 km
74955 7b Sallisaw 2 NW, OK 6.5 km
74962 7b Sallisaw 2 NW, OK 15.7 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.

Your own ZIP

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Other places to compare

These metros span exactly the same zones β€” 7b–8a β€” so the same plants are in and out of range across them. The freeze dates and the spring calendar are their own.

Gardening in Arkansas β€” zones 7a– 8b covers the whole state: how its 609 ZIP codes divide between 4 hardiness zones, and the freeze dates across every NOAA station in it.

Other metro areas in AR:

All 388 metro areas, by state

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 β€” the search is the honest version, and you choose.

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

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

All metro areas