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When to Plant Geraniums in Colleton County, SC

Colleton County, South Carolina Zone 8b June

Top priorities for Colleton County, South Carolina gardeners in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Colleton County, South Carolina.

Avg. last frost March 10
Avg. first frost November 13
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Pick geraniums

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Get ahead of July
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

Colleton County, South Carolina is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 13, giving you a growing season of approximately 248 days.

At an elevation of 265 feet, Colleton County receives approximately 58.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Geraniums may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Geraniums will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Geraniums root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Colleton County, SC (Zone 8b) Long season
248 days
Last Spring Frost March 10
248 growing days
First Fall Frost November 13

Colleton County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.9-6

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Dec 13 Transplant: Feb 7 🌸 Bloom: Apr 18 – Sep 19
Recommended (50%) ✓ Fits season (38 days to spare)
Start indoors: Dec 30 Transplant: Feb 24 🌸 Bloom: May 5 – Oct 6
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Jan 27 Transplant: Mar 24 🌸 Bloom: Jun 2 – Nov 3

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Colleton County

How your county's soil matches Geraniums's growing requirements.

Soil pH

Your soil pH (4.9–6.0) is more acidic than Geraniums prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Colleton County warms quickly in spring but drains fast. Geraniums will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Geraniums.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Geraniums.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Succession Planting Geraniums

4
successive plantings in your 248-day season

Sow every 8 weeks. Last sowing by Aug 05 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Geraniums

Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Geraniums Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 4.3" 6.2" 0" ✅ Rainfall sufficient
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.8" 0" ✅ Rainfall sufficient
Jul 4.3" 5.7" 0" ✅ Rainfall sufficient
Aug 4.3" 5.5" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 4" 0.3" 💧 Light watering
Dec 4.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Colleton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Geraniums Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Geraniums needs ~1,870 GDD — county provides 5,456 GDD Excellent fit

Geraniums Planting Timeline — Colleton County, SC

Geraniums Planting Calendar

Activity When Date Range
Start Indoors December 30 Dec 30 – Jan 13
Transplant Outdoors February 24 Feb 24 – Mar 10
Bloom May 5 May 5 – Oct 6

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
March Transplant Outdoors
April
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December Start Indoors

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

248 days in Colleton County

Growing Tips for Geraniums in Colleton County

Direct sow Geraniums outdoors after March 10 in Colleton County when soil has warmed and frost danger has passed.

Sandy soil in Colleton County dries quickly — mulch Geraniums with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Colleton County, provide afternoon shade for Geraniums and water deeply in the morning.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Geraniums in Colleton County, SC?

Colleton County is in Zone 8b with an average last frost of March 10. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Colleton County, SC?

Colleton County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 13.

🌱

Your Colleton County Garden Planner — Free

A 22-page printable planner built for Colleton County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Colleton County, SC. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.