Blog

When to Plant Chard in Clark County, MO

Clark County, Missouri Zone 6a May

Clark County, Missouri gardeners: here's your May plan

Here's what deserves your attention in Clark County, Missouri this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 16
Avg. first frost October 18
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Sow chard in trays indoors

    These need a head start before your last frost (April 16). Sow into cells now so you're ready to transplant in a few weeks.

Looking ahead to June
  • 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.

Clark County, Missouri is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 18, giving you a growing season of approximately 185 days.

At an elevation of 833 feet, Clark County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Chard during the growing season.

Clark County, MO (Zone 6a) Moderate season
185 days
Last Spring Frost April 16
185 growing days
First Fall Frost October 18
Share this guide:

Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (80 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 24
Recommended (50%) ✓ Fits season (80 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 30
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 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 Clark County

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

Soil pH

Your soil pH (5.6–6.6) overlaps with Chard's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Clark County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Chard.

How to Plant Chard

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

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

Succession Planting Chard

4
successive plantings in your 185-day season

Sow every 5.7 weeks. Last sowing by Aug 19 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 84 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 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3.5" 3.3" 0.2" 💧 Light watering
May 3.5" 4.1" 0" ✅ Rainfall sufficient
Jun 3.5" 3.7" 0" ✅ Rainfall sufficient
Jul 3.5" 3.3" 0.2" 💧 Light watering
Aug 3.5" 3.7" 0" ✅ Rainfall sufficient
Sep 3.5" 3.2" 0.3" 💧 Light watering
Oct 3.5" 2.6" 0.9" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clark 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 ~839 GDD — county provides 2,821 GDD Excellent fit

Chard Planting Timeline — Clark County, MO

Chard Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 2 Apr 2 – Apr 23
Harvest June 11 Jun 11 – Jul 30
Fall Sowing August 9 Aug 9 – Aug 23

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Fall Sowing
September
October
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: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

185 days in Clark County

Growing Tips for Chard in Clark County

Direct sow Chard outdoors after April 16 in Clark County when soil has warmed and frost danger has passed.

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 Clark County, MO?

Clark County is in Zone 6a with an average last frost of April 16. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, MO?

Clark County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 18.

🌱

Your Clark County Garden Planner — Free

A 24-page printable planner built for Clark County (Zone 6a). 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 Clark County, MO. 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.