What USDA hardiness zone is Colleton County, South Carolina?

Colleton County, South Carolina spans USDA hardiness zones 8b to 9a. 82% of its ZIP codes are zone 8b, so there is no single zone for the county.

When is the last spring frost in Colleton County, South Carolina?

The median last spring freeze runs March 1 – March 23 across the 4 NOAA weather stations serving Colleton County, South Carolina, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

South Carolina

Planting zones in Colleton County, South Carolina

This county spans USDA zones 8b to 9a, so there is no single zone for Colleton County and anyone who gives you one is rounding. 82% of its ZIP codes are zone 8b; the rest are not.

USDA zones 8b–9a 2 zones across 11 ZIP codes

ZIP codes 11 11 have a NOAA station within range

Weather stations 4 NOAA 1991–2020 normals, across 1,057 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Colleton County, South Carolina 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.

Colleton County does not have one planting answer

Its own weather stations disagree about 24 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: 233 days
YEMASSEE 1 N, SC US (USC00389469)
Longest season: 284 days
EDISTO IS MIDDLETON PLANTATION, SC US (USC00382735)

51 days of growing season separate those two stations, and both serve ZIP codes in Colleton 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 6 as growing season (228 days). Widening to any single station gives March 1 – December 6 (280 days).

That is a 52-day difference inside one county — 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

Colleton County covers 2 hardiness zones. A guide that gives the county one zone has picked whichever is largest and rounded everyone else into it — fine for the 82% in zone 8b and wrong for the other 18%. Here is the actual split.

Zone	ZIP codes	Share
8b	9	82%
9a	2	18%

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

Your freeze dates

Last spring freeze March 1 – March 23

First fall freeze November 6 – December 6

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 233–284 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 88.7–91 °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 16.0–19.2" 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. At the middle station that is covered, so watering in Colleton County is for the gaps between storms rather than the whole season. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 89 °F summer afternoon drying the soil faster than a cool one.

Every ZIP code in Colleton 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
29082	8b	Hampton 1S, SC	27.6 km
29435	8b	Walterboro 1 SW, SC	21.0 km
29446	9a	Edisto Is Middleton Plantation, SC	17.4 km
29452	9a	Edisto Is Middleton Plantation, SC	18.3 km
29474	8b	Walterboro 1 SW, SC	14.3 km
29475	8b	Walterboro 1 SW, SC	16.2 km
29481	8b	Walterboro 1 SW, SC	28.4 km
29488	8b	Walterboro 1 SW, SC	2.4 km
29493	8b	Walterboro 1 SW, SC	23.7 km
29929	8b	Hampton 1S, SC	22.4 km
29945	8b	Yemassee 1 N, SC	5.7 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 Colleton 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 4 – January 26	8 wk before
🌶️ Peppers	Start indoors	January 4 – January 26	8 wk before
🥦 Broccoli	Start indoors	January 18 – February 9	6 wk before
🥬 Cabbage	Start indoors	January 18 – February 9	6 wk before
🥬 Collards	Start indoors	January 18 – February 9	6 wk before
🥬 Kale	Start indoors	January 18 – February 9	6 wk before
🥬 Leaf Lettuce	Start indoors	January 18 – February 9	6 wk before
🫛 Peas	Direct sow	January 18 – February 9	6 wk before
🥬 Spinach	Direct sow	January 18 – February 9	6 wk before
🍠 Sweet Potato	Start indoors	January 18 – February 9	6 wk before
🍅 Tomatoes	Start indoors	January 18 – February 9	6 wk before
🥬 Bok Choy	Start indoors	January 25 – February 16	5 wk before
🥬 Kohlrabi	Start indoors	January 25 – February 16	5 wk before
🥬 Swiss Chard	Start indoors	January 25 – February 16	5 wk before
🥬 Arugula	Direct sow	February 1 – February 23	4 wk before
🥬 Baby Salad Greens	Direct sow	February 1 – February 23	4 wk before
🥕 Beets	Direct sow	February 1 – February 23	4 wk before
🧅 Green Onions	Direct sow	February 1 – February 23	4 wk before
🥬 Mustard Greens	Direct sow	February 1 – February 23	4 wk before
🌶️ Okra	Start indoors	February 1 – February 23	4 wk before
🌱 Radishes	Direct sow	February 1 – February 23	4 wk before
🥔 Turnips	Direct sow	February 1 – February 23	4 wk before
🥬 Cabbage	Set out	February 8 – March 2	3 wk before
🥕 Carrots	Direct sow	February 8 – March 2	3 wk before
🥬 Collards	Direct sow	February 8 – March 2	3 wk before
🥬 Collards	Set out	February 8 – March 2	3 wk before
🥒 Cucumbers	Start indoors	February 8 – March 2	3 wk before
🧅 Green Onions	Set out	February 8 – March 2	3 wk before
🥬 Kale	Direct sow	February 8 – March 2	3 wk before
🥬 Kale	Set out	February 8 – March 2	3 wk before
🥬 Kohlrabi	Direct sow	February 8 – March 2	3 wk before
🥬 Kohlrabi	Set out	February 8 – March 2	3 wk before
🥬 Leaf Lettuce	Direct sow	February 8 – March 2	3 wk before
🎃 Pumpkins	Start indoors	February 8 – March 2	3 wk before
🎃 Summer Squash	Start indoors	February 8 – March 2	3 wk before
🎃 Winter Squash	Start indoors	February 8 – March 2	3 wk before
🥒 Zucchini	Start indoors	February 8 – March 2	3 wk before
🥬 Bok Choy	Direct sow	February 15 – March 9	2 wk before
🥬 Bok Choy	Set out	February 15 – March 9	2 wk before
🥦 Broccoli	Set out	February 15 – March 9	2 wk before
🌿 Cilantro	Direct sow	February 15 – March 9	2 wk before
🥬 Leaf Lettuce	Set out	February 15 – March 9	2 wk before
🥬 Swiss Chard	Direct sow	February 15 – March 9	2 wk before
🥬 Swiss Chard	Set out	February 15 – March 9	2 wk before
🌿 Dill	Direct sow	February 22 – March 16	1 wk before
🫘 Bush Beans	Direct sow	March 8 – March 30	1 wk after
🥒 Cucumbers	Set out	March 8 – March 30	1 wk after
🎃 Pumpkins	Direct sow	March 8 – March 30	1 wk after
🎃 Pumpkins	Set out	March 8 – March 30	1 wk after
🎃 Summer Squash	Direct sow	March 8 – March 30	1 wk after
🎃 Summer Squash	Set out	March 8 – March 30	1 wk after
🌽 Sweet Corn	Direct sow	March 8 – March 30	1 wk after
🍅 Tomatoes	Set out	March 8 – March 30	1 wk after
🎃 Winter Squash	Direct sow	March 8 – March 30	1 wk after
🎃 Winter Squash	Set out	March 8 – March 30	1 wk after
🥒 Zucchini	Direct sow	March 8 – March 30	1 wk after
🥒 Zucchini	Set out	March 8 – March 30	1 wk after
🥒 Cucumbers	Direct sow	March 15 – April 6	2 wk after
🌶️ Okra	Direct sow	March 15 – April 6	2 wk after
🌶️ Okra	Set out	March 15 – April 6	2 wk after
🌶️ Peppers	Set out	March 15 – April 6	2 wk after
🫘 Southern Peas	Direct sow	March 15 – April 6	2 wk after
🍠 Sweet Potato	Set out	March 15 – 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 survives the winter changes across Colleton County

Zone 8b carries 54 of 74 perennial edibles; zone 9a carries 46. The best number is not always the warmest zone — the count peaks in the middle and falls both ways, because the warm end loses plants to insufficient winter chill and summer heat, not to cold.

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.

At least one station here freezes across the new year, which puts the two ends of a spread on opposite sides of the calendar. Drawing it would produce a bar spanning almost the whole year and meaning nothing, so none is drawn.

The 4 stations behind these numbers

All 4 NOAA stations whose normals this page quotes, spanning about 31 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
Edisto Is Middleton Plantation, SC	USC00382735	March 1	December 6	284 days
Hampton 1S, SC	USC00383906	March 6	November 26	267 days
Walterboro 1 SW, SC	USC00388922	March 19	November 12	239 days
Yemassee 1 N, SC	USC00389469	March 23	November 6	233 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

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

More of South Carolina

Counties with the same zones — 8b–9a

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.

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.

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.