Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 29551 — Hartsville, SC

ZIP code 29551 (Hartsville, Darlington County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 30 and the first fall frost November 6.

Where ZIP 29551 is

tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostMar 30

First frostNov 6

2012 zone8a

Was 8a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hartsville, SC…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Hartsville, SC

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 30median — 50% chance of a later frost

Safe for tender plantsApril 13only 10% chance of frost after

First fall frostNovember 6median — 10% chance by Oct 26

Growing season224 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 16 and returns around November 18.

From the NOAA station Hartsville, SC — 5 miles away, elevation 184 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 29551

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 16 – Mar 2

SpinachSow outdoors · Feb 16 – Mar 9

Broccoli, cabbageStart indoors · Jan 19 – Feb 2

Broccoli, cabbageTransplant · Mar 9 – Mar 23

Onion setsPlant outdoors · Mar 2 – Mar 16

PotatoesPlant outdoors · Mar 9 – Mar 23

LettuceSow outdoors · Mar 2 – Mar 16

Carrots, beetsSow outdoors · Mar 9 – Mar 23

TomatoesStart indoors · Feb 2 – Feb 16

TomatoesTransplant · Apr 6 – Apr 20

Peppers, eggplantStart indoors · Jan 19 – Feb 2

Peppers, eggplantTransplant · Apr 13 – Apr 27

BeansSow outdoors · Apr 6 – Apr 20

Sweet cornSow outdoors · Apr 6 – Apr 20

Cucumbers, squashSow outdoors · Apr 6 – Apr 20

Fall lettuce, spinachSow outdoors · Sep 11 – Sep 25

GarlicPlant cloves · Oct 23 – Nov 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 30) and first fall frost (Nov 6) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 29551 came on Feb 17 — 8 days later than the 1991–2020 average (Feb 9).

average
Feb 92026
Feb 17

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 8b in South Carolina

566 plants native to the lower 48 states, recorded in South Carolina, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Hartsville, SC.

Soil in Hartsville, SC

The soil mapped at the center of ZIP 29551 is Johnston — sandy loam, very poorly drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter5.5%high

Hydrologic groupA/Ddrains fast once dried out; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Johnston sandy loam, 0 to 2 percent slopes,frequently flooded.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 29551; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hartsville, SC

Summer high92 °Faverage high, July

Winter low32 °Faverage low, January

Hot days74days a year at 90 °F or more

Freezing nights62nights a year at 32 °F or less

Growing degree days5,336base 50 °F — the season’s usable heat

Longest day14 h 27 mindaylight on June 21

Shortest day9 h 51 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation48.5 inper year, rain and melted snow

Snowfall1 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hartsville, SC (5 mi away); precipitation: Hartsville, SC (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

295508b

Hartsville, SC · 4 mi

Bishopville, SC · 13 mi

Darlington, SC · 16 mi

All 2 ZIP codes in Hartsville → · South Carolina planting zones →

Questions about 29551

What planting zone is ZIP code 29551?

ZIP code 29551 (Hartsville, SC) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Hartsville, SC?

The median last spring frost (32 °F) near 29551 is March 30; after April 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hartsville station.

When is the first frost in Hartsville, SC?

The median first fall frost near 29551 is November 6, giving a median frost-free growing season of 224 days.

When should I plant tomatoes in 29551?

Start tomato seeds indoors around Feb 2 – Feb 16 and set transplants outside around Apr 6 – Apr 20, one to three weeks after the median last frost.

How much rain and snow does 29551 get?

About 48.5 inches of precipitation a year and 1 inches of snowfall (NOAA 1991–2020 normals, Hartsville station).

How hot do summers get in Hartsville, SC?

The average high peaks at 92 °F in July, with about 74 days a year at 90 °F or more.

What kind of soil does 29551 have?

The USDA soil survey maps Johnston at the center of ZIP 29551: sandy loam, very poorly drained, pH about 5.0 (strongly acidic).

Did spring come early in Hartsville, SC in 2026?

Spring leaf-out near 29551 came on Feb 17 in 2026, 8 days later than the 1991–2020 average (Feb 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hartsville, SC?

Intermediate onions: the longest day near 29551 is 14 h 27 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 29551 change?

Yes. The 2012 USDA map put 29551 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.