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When to Plant Chard in Adair County, OK

Adair County, Oklahoma Zone 7b May

Your May planting checklist for Adair County, Oklahoma

A quick May briefing for Adair County, Oklahoma gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 7
Avg. first frost October 27
Soil temp (4") 66°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Begin indoor sowing: chard

    Label every cell. You will absolutely forget which is which otherwise.

Looking ahead to June
  • 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.

Adair County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is October 27, giving you a growing season of approximately 203 days.

At an elevation of 486 feet, Adair County receives approximately 33.9 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Chard during the growing season.

Adair County, OK (Zone 7b) Long season
203 days
Last Spring Frost April 7
203 growing days
First Fall Frost October 27
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Adair County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 23 – Jul 11
Recommended (50%) ✓ Fits season (98 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jul 21
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 8

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 Adair County

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

Soil pH

Your soil pH (6.7–7.1) overlaps with Chard's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Adair 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

4
successive plantings in your 203-day season

Sow every 5.7 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant 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 178 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" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.5" 4.2" 0" ✅ Rainfall sufficient
May 3.5" 4.5" 0" ✅ Rainfall sufficient
Jun 3.5" 5.5" 0" ✅ Rainfall sufficient
Jul 3.5" 4.1" 0" ✅ Rainfall sufficient
Aug 3.5" 3.6" 0" ✅ Rainfall sufficient
Sep 3.5" 3.1" 0.4" 💧 Light watering
Oct 3.5" 2.4" 1.1" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Adair 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 ~1,086 GDD — county provides 4,009 GDD Excellent fit

Chard Planting Timeline — Adair County, OK

Chard Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 24 Mar 24 – Apr 14
Harvest June 2 Jun 2 – Jul 21
Fall Sowing August 18 Aug 18 – Sep 1

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 Fall Sowing
October
November
December
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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 7b

📆 Growing Season

203 days in Adair County

Growing Tips for Chard in Adair County

Direct sow Chard outdoors after April 07 in Adair County when soil has warmed and frost danger has passed.

Summer highs in Adair County reach 93°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 Adair County, OK?

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

What planting zone is Adair County, OK?

Adair County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is October 27.

🌱

Your Adair County Garden Planner — Free

A 24-page printable planner built for Adair County (Zone 7b). 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 Adair County, OK. 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.