Blog

When to Plant Chard in Charleston County, SC

Charleston County, South Carolina Zone 9a May

Top priorities for Charleston County, South Carolina gardeners in May

Here's what deserves your attention in Charleston County, South Carolina this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 6
Avg. first frost November 17
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Bring in the chard

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

June prep starts now
  • First harvests: chard

Instant PDF download. No spam, unsubscribe any time.

Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

Charleston County, South Carolina is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 17, giving you a growing season of approximately 256 days.

At an elevation of 275 feet, Charleston County receives approximately 48.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Chard may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Chard will need more frequent watering and organic matter to retain nutrients.

Charleston County, SC (Zone 9a) Long season
256 days
Last Spring Frost March 6
256 growing days
First Fall Frost November 17
Share this guide:

Charleston County Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (158 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🍅 Harvest: Apr 17 – Jun 5
Recommended (50%) ✓ Fits season (151 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: May 1 – Jun 19
Safe Start (90%) ✓ Fits season (151 days to spare)
Start indoors: Mar 1 Transplant: Mar 29 🍅 Harvest: May 24 – Jul 12

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 Charleston County

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

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Chard

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Chard

6
successive plantings in your 256-day season

Sow every 5.7 weeks. Last sowing by Sep 18 to harvest before frost.

For a dedicated fall crop, sow by Sep 22.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.8″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 25 gal / 100 sq ft

Monthly Watering Guide for Chard

Chard 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 Chard Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 3.5" 4.8" 0" ✅ Rainfall sufficient
Apr 3.5" 3.1" 0.4" 💧 Light watering
May 3.5" 4" 0" ✅ Rainfall sufficient
Jun 3.5" 4" 0" ✅ Rainfall sufficient
Jul 3.5" 5.2" 0" ✅ Rainfall sufficient
Aug 3.5" 4.2" 0" ✅ Rainfall sufficient
Sep 3.5" 4.1" 0" ✅ Rainfall sufficient
Oct 3.5" 2.6" 0.9" 💧 Light watering
Nov 3.5" 3.7" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

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

Chard 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.

Chard needs ~1,169 GDD — county provides 5,440 GDD Excellent fit

Chard Planting Timeline — Charleston County, SC

Chard Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors March 6 Mar 6 – Mar 20
Direct Sow February 13 Feb 13 – Mar 6
Harvest May 1 May 1 – Jun 19
Fall Sowing September 22 Sep 22 – Oct 6

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April
May Harvest
June Harvest
July
August
September Fall Sowing
October Fall Sowing
November
December
Share this guide:

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

256 days in Charleston County

Growing Tips for Chard in Charleston County

Direct sow Chard outdoors after March 06 in Charleston County when soil has warmed and frost danger has passed.

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

Summer highs in Charleston County reach 95°F — grow Chard as a spring or fall crop. Use shade cloth if planting in summer.

General growing tips

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chard in Charleston County, SC?

Charleston County is in Zone 9a with an average last frost of March 6. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Charleston County, SC?

Charleston County, South Carolina is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 17.

🌱

Your Charleston County Garden Planner — Free

A 24-page printable planner built for Charleston County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Charleston 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.