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When to Plant Zucchini in Calhoun County, SC

Calhoun County, South Carolina Zone 8b May

May to-do list for Calhoun County, South Carolina

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

Avg. last frost March 17
Avg. first frost November 17
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Bring in the zucchini

    If you can't use it all right away, check the food-preservation section of your planner.

Coming up in June — start thinking about
  • First harvests: zucchini

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Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Calhoun County, South Carolina is in USDA Zone 8b. 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 Zucchini during the growing season. Sandy soil warms quickly in spring — great for early planting — but Zucchini will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Zucchini root diseases.

Calhoun County, SC (Zone 8b) 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 (126 days to spare)
Start indoors: Feb 8 Transplant: Mar 22 🍅 Harvest: May 10 – Jul 5
Recommended (50%) ✓ Fits season (126 days to spare)
Start indoors: Feb 17 Transplant: Mar 31 🍅 Harvest: May 19 – Jul 14
Safe Start (90%) ✓ Fits season (125 days to spare)
Start indoors: Mar 3 Transplant: Apr 14 🍅 Harvest: Jun 2 – Jul 28

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 Zucchini's growing requirements.

Soil pH

Your soil pH (5.0–6.3) is more acidic than Zucchini prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Calhoun County warms quickly in spring but drains fast. Zucchini 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 Zucchini.

How to Plant Zucchini

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Zucchini

6
successive plantings in your 245-day season

Sow every 5.1 weeks. Last sowing by Sep 18 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.9″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 695 gal / 100 sq ft

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan 4.1" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 5.2" 5.3" 0" ✅ Rainfall sufficient
Apr 5.2" 3.2" 2" 💧 Light watering
May 5.2" 4.4" 0.8" 💧 Light watering
Jun 5.2" 4.9" 0.3" 💧 Light watering
Jul 5.2" 5.7" 0" ✅ Rainfall sufficient
Aug 5.2" 5" 0.2" 💧 Light watering
Sep 5.2" 3.9" 1.3" 💧 Light watering
Oct 5.2" 3" 2.2" 💧 Light watering
Nov 5.2" 3.9" 1.3" 💧 Light watering
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.

Zucchini 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.

Zucchini needs ~998 GDD — county provides 4,655 GDD Excellent fit

Zucchini Planting Timeline — Calhoun County, SC

Zucchini Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 – Mar 3
Transplant Outdoors March 31 Mar 31 – Apr 14
Direct Sow March 24 Mar 24 – Apr 14
Harvest May 19 May 19 – Jul 14

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

245 days in Calhoun County

Growing Tips for Zucchini in Calhoun County

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

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

Your generous 245.0-day season in Calhoun County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.

Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Calhoun County, SC?

Calhoun County is in Zone 8b with an average last frost of March 17. Plan your Zucchini 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 8b. The average last spring frost is March 17 and first fall frost is November 17.

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Your Calhoun County Garden Planner — Free

A 24-page printable planner built for Calhoun 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 Calhoun County, SC. Local conditions may vary. Last updated: May 2026.

Sources & credits

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