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

Planting zone for Johns Island, SC

Johns Island, SC is in USDA zone 9a across its 2 ZIP codes. The median last spring frost is February 4 and the first fall frost December 30.

Johns Island on the zone map

Outlined: its 1 ZIP code areas · 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
ZIP codes2
Last frostFeb 4
First frostDec 30
Growing season321 days

9a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Johns Island, SC

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 4median — 50% chance of a later frost
Safe for tender plantsMarch 4only 10% chance of frost after
First fall frostDecember 30median — 10% chance by Dec 2
Growing season321 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 24 and returns around January 8.

From the NOAA station Charleston City, SC, elevation 10 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 Johns Island

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 24 – Jan 7
SpinachSow outdoors · Dec 24 – Jan 14
Broccoli, cabbageStart indoors · Nov 26 – Dec 10
Broccoli, cabbageTransplant · Jan 14 – Jan 28
Onion setsPlant outdoors · Jan 7 – Jan 21
PotatoesPlant outdoors · Jan 14 – Jan 28
LettuceSow outdoors · Jan 7 – Jan 21
Carrots, beetsSow outdoors · Jan 14 – Jan 28
TomatoesStart indoors · Dec 10 – Dec 24
TomatoesTransplant · Feb 11 – Feb 25
Peppers, eggplantStart indoors · Nov 26 – Dec 10
Peppers, eggplantTransplant · Feb 18 – Mar 4
BeansSow outdoors · Feb 11 – Feb 25
Sweet cornSow outdoors · Feb 11 – Feb 25
Cucumbers, squashSow outdoors · Feb 11 – Feb 25
Fall lettuce, spinachSow outdoors · Nov 4 – Nov 18
GarlicPlant cloves · Dec 16 – Jan 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 4) and first fall frost (Dec 30) 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 29457 came on Feb 7 — 7 days later than the 1991–2020 average (Jan 31).

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.

Trees 83

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 133

Allegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Faloe yucca15 ft · blooms early summer · medium shade tolerance · to −1 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 170

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 169

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 12

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °F

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 Johns Island, SC.

Soil in Johns Island, SC

The soil mapped at the center of ZIP 29457 is Wadmalaw — fine sandy loam, poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH4.7strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter1.5%low — add compost
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Wadmalaw fine sandy loam.

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 29457; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Johns Island, SC

Summer high91 °Faverage high, July
Winter low39 °Faverage low, January
Hot days64days a year at 90 °F or more
Freezing nights22nights a year at 32 °F or less
Growing degree days6,385base 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
Precipitation52.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 60 °F, low 39 °F 60°39° JanFebruary: average high 64 °F, low 42 °F 64°42° FebMarch: average high 70 °F, low 47 °F 70°47° MarApril: average high 77 °F, low 55 °F 77°55° AprMay: average high 84 °F, low 63 °F 84°63° MayJune: average high 89 °F, low 70 °F 89°70° JunJuly: average high 91 °F, low 74 °F 91°74° JulAugust: average high 90 °F, low 73 °F 90°73° AugSeptember: average high 85 °F, low 68 °F 85°68° SepOctober: average high 78 °F, low 58 °F 78°58° OctNovember: average high 69 °F, low 47 °F 69°47° NovDecember: average high 63 °F, low 42 °F 63°42° Dec

Precipitation by month inches

0″2″4″6″January: 3.63 in precipitation 3.6 JanFebruary: 3.41 in precipitation 3.4 FebMarch: 3.50 in precipitation 3.5 MarApril: 3.14 in precipitation 3.1 AprMay: 3.80 in precipitation 3.8 MayJune: 5.35 in precipitation 5.3 JunJuly: 6.63 in precipitation 6.6 JulAugust: 6.41 in precipitation 6.4 AugSeptember: 5.48 in precipitation 5.5 SepOctober: 4.43 in precipitation 4.4 OctNovember: 2.69 in precipitation 2.7 NovDecember: 3.78 in precipitation 3.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Charleston Intl Airport, SC (8 mi away); precipitation: Charleston 5.0 Wnw, SC (2 mi away). Daylight is calculated from latitude.

ZIP codes in Johns Island

294559a
20 to 25 °F
294579a
20 to 25 °F

South Carolina planting zones →

Questions about Johns Island

What planting zone is Johns Island, SC?

Johns Island, SC is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Johns Island, SC?

The median last spring frost is February 4 and the median first fall frost is December 30 (NOAA 1991–2020 normals, Charleston City station).

When can I plant a garden in Johns Island, SC?

Cool-season crops like peas and spinach go in around Dec 24 – Jan 14; tomatoes, peppers, beans and squash after about Feb 11, once frost risk has passed.

What kind of onions grow in Johns Island, SC?

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

How much rain and snow does Johns Island, SC get?

About 52.3 inches of precipitation a year (NOAA 1991–2020 normals).