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When to Plant Leeks in Calhoun County, SC

Calhoun County, South Carolina Zone 8a April

April to-do list for Calhoun County, South Carolina

We've pulled the most time-sensitive tasks for Calhoun County, South Carolina this April and put them front and centre. Tackle them in order.

Avg. last frost March 17
Avg. first frost November 17
Soil temp (4") 61°F
Watering Moderate
Pest pressure High
Daylight 12.8 hrs
  1. Begin indoor sowing: leeks

    These need a head start before your last frost (March 17). Sow into cells now so you're ready to transplant in a few weeks.

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Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

Calhoun County, South Carolina is in USDA Zone 8a. The average last spring frost is March 17 and the first fall frost is November 17, giving you a growing season of approximately 245 days.

At an elevation of 447 feet, Calhoun County receives approximately 51.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Leeks during the growing season. Sandy soil warms quickly in spring — great for early planting — but Leeks will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks root diseases.

Calhoun County, SC (Zone 8a) Long season
245 days
Last Spring Frost March 17
245 growing days
First Fall Frost November 17
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Calhoun County Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Start indoors: Feb 1 Transplant: Mar 8 🍅 Harvest: Jun 7 – Aug 23
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Feb 10 Transplant: Mar 17 🍅 Harvest: Jun 16 – Sep 1
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: Jun 30 – Sep 15

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 Calhoun County

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

Soil pH

Your soil pH (5.0–6.3) is more acidic than Leeks prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Leeks.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

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

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 4.1" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 3.5" 5.3" 0" ✅ Rainfall sufficient
Apr 3.5" 3.2" 0.3" 💧 Light watering
May 3.5" 4.4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.9" 0" ✅ Rainfall sufficient
Jul 3.5" 5.7" 0" ✅ Rainfall sufficient
Aug 3.5" 5" 0" ✅ Rainfall sufficient
Sep 3.5" 3.9" 0" ✅ Rainfall sufficient
Oct 3.5" 3" 0.5" 💧 Light watering
Nov 3.5" 3.9" 0" ✅ Rainfall sufficient
Dec 3.9" 0" ❄️ Dormant

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

Leeks 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.

Leeks needs ~2,280 GDD — county provides 4,655 GDD Excellent fit

Leeks Planting Timeline — Calhoun County, SC

Leeks Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors March 17 Mar 17 – Mar 31
Direct Sow March 3 Mar 3 – Mar 24
Harvest June 16 Jun 16 – Sep 1
Fall Sowing September 8 Sep 8 – Sep 22

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April
May
June Harvest
July Harvest
August Harvest
September Fall Sowing Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8a

📆 Growing Season

245 days in Calhoun County

Growing Tips for Leeks in Calhoun County

Direct sow Leeks outdoors after March 17 in Calhoun County when soil has warmed and frost danger has passed.

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

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Calhoun County, SC?

Calhoun County is in Zone 8a with an average last frost of March 17. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calhoun County, SC?

Calhoun County, South Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 17 and first fall frost is November 17.

🌱

Your Calhoun County Garden Planner — Free

A 24-page printable planner built for Calhoun County (Zone 8a). 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 Calhoun County, SC. Local conditions may vary. Last updated: April 2026.

Sources & credits

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