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When to Plant Chard in Hardin County, IL

Hardin County, Illinois Zone 7a May

Your May game plan for Hardin County, Illinois

Each item below is timed to Hardin County, Illinois's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 4
Avg. first frost October 31
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Indoor seed-starting week for chard

    You're about 26 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Collect chard at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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

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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.

Hardin County, Illinois is in USDA Zone 7a. The average last spring frost is April 4 and the first fall frost is October 31, giving you a growing season of approximately 210 days.

At an elevation of 1,218 feet, Hardin County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Chard during the growing season.

Hardin County, IL (Zone 7a) Long season
210 days
Last Spring Frost April 4
210 growing days
First Fall Frost October 31

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (103 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 23 – Jul 11
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 30 – Jul 18
Safe Start (90%) ✓ Fits season (113 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 12 – Jul 31

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 Hardin County

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Chard's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Chard will thrive.

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

5
successive plantings in your 210-day season

Sow every 5.7 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.6″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 366 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 1.2" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3.5" 3.2" 0.3" 💧 Light watering
May 3.5" 3.1" 0.4" 💧 Light watering
Jun 3.5" 3.4" 0.1" 💧 Light watering
Jul 3.5" 3" 0.5" 💧 Light watering
Aug 3.5" 3.4" 0.1" 💧 Light watering
Sep 3.5" 2.8" 0.7" 💧 Light watering
Oct 3.5" 2.7" 0.8" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hardin 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 ~880 GDD — county provides 3,360 GDD Excellent fit

Chard Planting Timeline — Hardin County, IL

Chard Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 21 Mar 21 – Apr 11
Harvest May 30 May 30 – Jul 18
Fall Sowing August 22 Aug 22 – Sep 5

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

Month-by-Month Timeline

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

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 7a

📆 Growing Season

210 days in Hardin County

Growing Tips for Chard in Hardin County

Direct sow Chard outdoors after April 04 in Hardin 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 Hardin County, IL?

Hardin County is in Zone 7a with an average last frost of April 4. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardin County, IL?

Hardin County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 4 and first fall frost is October 31.

🌱

Your Hardin County Garden Planner — Free

A 24-page printable planner built for Hardin County (Zone 7a). 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 Hardin County, IL. 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.