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When to plant Chard in Randolph County, IL

The best window to plant Chard in Randolph County, is March 28–April 18, when soil warms to 50°F. Last frost typically hits April 11; first frost October 20. A second sowing from August 11 to August 25 extends the harvest into fall.

When to Plant Chard in Randolph County, IL

Randolph County, Illinois Zone 7a July

Randolph County, Illinois gardeners: here's your July plan

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 11
Avg. first frost October 20
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 14.4 hrs
  1. Basket week: chard

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

August will be here before you know it — start on
  • Fall sowing: 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.

Randolph County, Illinois is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 20, giving you a growing season of approximately 192 days.

At an elevation of 501 feet, Randolph County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Chard during the growing season.

Randolph County, IL (Zone 7a) Moderate season
192 days
Last Spring Frost April 11
192 growing days
First Fall Frost October 20

Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Chard Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: May 31 – Jul 19
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jun 6 – Jul 25
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 6

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 Randolph County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Chard's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — 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

4
successive plantings in your 192-day season

Sow every 5.7 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Chard Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 169 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.5" 3.2" 0.3" 💧 Light watering
May 3.5" 4.1" 0" ✅ Rainfall sufficient
Jun 3.5" 4.3" 0" ✅ Rainfall sufficient
Jul 3.5" 3.6" 0" ✅ Rainfall sufficient
Aug 3.5" 3" 0.5" 💧 Light watering
Sep 3.5" 3.2" 0.3" 💧 Light watering
Oct 3.5" 2.4" 1.1" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Randolph 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 ~798 GDD — county provides 2,784 GDD Excellent fit

Chard Planting Timeline — Randolph County, IL

Chard Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow March 28 Mar 28 – Apr 18
Harvest June 6 Jun 6 – Jul 25
Fall Sowing August 11 Aug 11 – Aug 25

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

Month-by-Month Timeline

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

192 days in Randolph County

Growing Tips for Chard in Randolph County

Direct sow Chard outdoors after April 11 in Randolph 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 Randolph County, IL?

Randolph County is in Zone 7a with an average last frost of April 11. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, IL?

Randolph County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 20.

When should I plant Chard in Randolph County, IL?

In Randolph County, IL, plant Chard after the last frost (around April 11) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Randolph County, IL for Chard?

Randolph County sits in USDA Zone 7a. Chard grows reliably in zones 2a through 11b, so it's a good fit here.

Can Chard grow in Randolph County's climate?

Yes — Chard grows well in Randolph County's temperate climate. Randolph County averages a 192-day frost-free season, with last frost around April 11 and first frost around October 20.

🌱

Your Randolph County Garden Planner — Free

A 22-page printable planner built for Randolph 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 Randolph County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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