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

Planting zone for 29063 — Irmo, SC

ZIP code 29063 (Irmo, Richland County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 10 and the first fall frost October 28.

Where ZIP 29063 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.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostApr 10

First frostOct 28

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 Irmo, 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 Irmo, SC

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 10median — 50% chance of a later frost

Safe for tender plantsApril 23only 10% chance of frost after

First fall frostOctober 28median — 10% chance by Oct 15

Growing season201 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around November 5.

From the NOAA station Cedar Creek 2e, SC — 9 miles away, elevation 338 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 29063

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 27 – Mar 13

SpinachSow outdoors · Feb 27 – Mar 20

Broccoli, cabbageStart indoors · Jan 30 – Feb 13

Broccoli, cabbageTransplant · Mar 20 – Apr 3

Onion setsPlant outdoors · Mar 13 – Mar 27

PotatoesPlant outdoors · Mar 20 – Apr 3

LettuceSow outdoors · Mar 13 – Mar 27

Carrots, beetsSow outdoors · Mar 20 – Apr 3

TomatoesStart indoors · Feb 13 – Feb 27

TomatoesTransplant · Apr 17 – May 1

Peppers, eggplantStart indoors · Jan 30 – Feb 13

Peppers, eggplantTransplant · Apr 24 – May 8

BeansSow outdoors · Apr 17 – May 1

Sweet cornSow outdoors · Apr 17 – May 1

Cucumbers, squashSow outdoors · Apr 17 – May 1

Fall lettuce, spinachSow outdoors · Sep 2 – Sep 16

GarlicPlant cloves · Oct 14 – Nov 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 10) and first fall frost (Oct 28) 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 29063 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 Irmo, SC.

Soil in Irmo, SC

The soil mapped at the center of ZIP 29063 is Georgeville — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Georgeville silt loam, 2 to 6 percent slopes.

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 29063; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Irmo, SC

Summer high90 °Faverage high, July

Winter low29 °Faverage low, January

Hot days71days a year at 90 °F or more

Freezing nights95nights a year at 32 °F or less

Growing degree days4,723base 50 °F — the season’s usable heat

Longest day14 h 26 mindaylight on June 21

Shortest day9 h 52 mindaylight on December 21

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

Precipitation45.9 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: Cedar Creek 2e, SC (9 mi away); precipitation: Irmo 4.2 Nnw, SC (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

290028b

Ballentine, SC · 2 mi

291778b

White Rock, SC · 4 mi

South Carolina planting zones →

Questions about 29063

What planting zone is ZIP code 29063?

ZIP code 29063 (Irmo, 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 Irmo, SC?

The median last spring frost (32 °F) near 29063 is April 10; after April 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cedar Creek 2e station.

When is the first frost in Irmo, SC?

The median first fall frost near 29063 is October 28, giving a median frost-free growing season of 201 days.

When should I plant tomatoes in 29063?

Start tomato seeds indoors around Feb 13 – Feb 27 and set transplants outside around Apr 17 – May 1, one to three weeks after the median last frost.

How much rain and snow does 29063 get?

About 45.9 inches of precipitation a year (NOAA 1991–2020 normals, Irmo 4.2 Nnw station).

How hot do summers get in Irmo, SC?

The average high peaks at 90 °F in July, with about 71 days a year at 90 °F or more.

What kind of soil does 29063 have?

The USDA soil survey maps Georgeville at the center of ZIP 29063: silt loam, well drained, pH about 5.8 (moderately acidic).

Did spring come early in Irmo, SC in 2026?

Spring leaf-out near 29063 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 Irmo, SC?

Intermediate onions: the longest day near 29063 is 14 h 26 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 29063 change?

Yes. The 2012 USDA map put 29063 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.