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

Planting zone for 29426 — Adams Run, SC

ZIP code 29426 (Adams Run, Charleston County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 1 and the first fall frost December 6.

Where ZIP 29426 is

Outlined: the ZIP code area · 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.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostMar 1

First frostDec 6

2012 zone8b

Was 8b 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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Adams Run, 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 Adams Run, SC

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 1median — 50% chance of a later frost

Safe for tender plantsMarch 22only 10% chance of frost after

First fall frostDecember 6median — 10% chance by Nov 15

Growing season284 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 10 and returns around December 29.

From the NOAA station Edisto Is Middleton Plantation, SC — 12 miles away, elevation 13 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 29426

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 18 – Feb 1

SpinachSow outdoors · Jan 18 – Feb 8

Broccoli, cabbageStart indoors · Dec 21 – Jan 4

Broccoli, cabbageTransplant · Feb 8 – Feb 22

Onion setsPlant outdoors · Feb 1 – Feb 15

PotatoesPlant outdoors · Feb 8 – Feb 22

LettuceSow outdoors · Feb 1 – Feb 15

Carrots, beetsSow outdoors · Feb 8 – Feb 22

TomatoesStart indoors · Jan 4 – Jan 18

TomatoesTransplant · Mar 8 – Mar 22

Peppers, eggplantStart indoors · Dec 21 – Jan 4

Peppers, eggplantTransplant · Mar 15 – Mar 29

BeansSow outdoors · Mar 8 – Mar 22

Sweet cornSow outdoors · Mar 8 – Mar 22

Cucumbers, squashSow outdoors · Mar 8 – Mar 22

Fall lettuce, spinachSow outdoors · Oct 11 – Oct 25

GarlicPlant cloves · Nov 22 – Dec 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 1) and first fall frost (Dec 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 29426 came on Feb 14 — 14 days later than the 1991–2020 average (Jan 31).

average
Jan 312026
Feb 14

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 9a in South Carolina

578 plants native to the lower 48 states, recorded in South Carolina, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. 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 Adams Run, SC.

Soil in Adams Run, SC

The soil mapped at the center of ZIP 29426 is Rutlege — loamy fine sand, very poorly drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding

pH4.6strongly acidic; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter3%moderate

Hydrologic groupA/Ddrains fast once dried out; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Rutlege-Pamlico complex.

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 29426; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Adams Run, SC

Summer high90 °Faverage high, July

Winter low40 °Faverage low, January

Hot days73days a year at 90 °F or more

Freezing nights16nights a year at 32 °F or less

Growing degree days6,408base 50 °F — the season’s usable heat

Longest day14 h 19 mindaylight on June 21

Shortest day9 h 59 mindaylight on December 21

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

Precipitation52.6 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Edisto Is Middleton Plantation, SC (12 mi away); precipitation: Meggett 1.8 W, SC (7 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.

294529a

Jacksonboro, SC · 7 mi

Wadmalaw Island, SC · 14 mi

294358b

Cottageville, SC · 14 mi

294389a

Edisto Island, SC · 15 mi

294858b

Summerville, SC · 15 mi

South Carolina planting zones →

Questions about 29426

What planting zone is ZIP code 29426?

ZIP code 29426 (Adams Run, SC) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Adams Run, SC?

The median last spring frost (32 °F) near 29426 is March 1; after March 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Edisto Is Middleton Plantation station.

When is the first frost in Adams Run, SC?

The median first fall frost near 29426 is December 6, giving a median frost-free growing season of 284 days.

When should I plant tomatoes in 29426?

Start tomato seeds indoors around Jan 4 – Jan 18 and set transplants outside around Mar 8 – Mar 22, one to three weeks after the median last frost.

How much rain and snow does 29426 get?

About 52.6 inches of precipitation a year (NOAA 1991–2020 normals, Meggett 1.8 W station).

How hot do summers get in Adams Run, SC?

The average high peaks at 90 °F in July, with about 73 days a year at 90 °F or more.

What kind of soil does 29426 have?

The USDA soil survey maps Rutlege at the center of ZIP 29426: loamy fine sand, very poorly drained, pH about 4.6 (strongly acidic).

Did spring come early in Adams Run, SC in 2026?

Spring leaf-out near 29426 came on Feb 14 in 2026, 14 days later than the 1991–2020 average (Jan 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Adams Run, SC?

Intermediate onions: the longest day near 29426 is 14 h 19 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 29426 change?

Yes. The 2012 USDA map put 29426 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.