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When to Plant Chard in Ellis County, OK

Ellis County, Oklahoma Zone 7a May

Your May gardening checklist

May is a pivotal month for Ellis County, Oklahoma gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 16
Avg. first frost October 22
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 13.9 hrs
  1. Start chard under lights

    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.

Before June arrives, get these ready
  • 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.

Ellis County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.

At an elevation of 968 feet, Ellis County receives approximately 28.1 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Chard during the growing season.

Ellis County, OK (Zone 7a) Moderate season
189 days
Last Spring Frost April 16
189 growing days
First Fall Frost October 22
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Ellis County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Jun 7 – Jul 26
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 30
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 14

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 Ellis County

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

Soil pH

Your soil pH (6.8–7.7) is more alkaline than Chard prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Chard.

Organic Matter

Organic matter is moderate (4.0%). 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 189-day season

Sow every 5.7 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 839 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 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 3.5" 2.7" 0.8" 💧 Light watering
May 3.5" 3.9" 0" ✅ Rainfall sufficient
Jun 3.5" 5" 0" ✅ Rainfall sufficient
Jul 3.5" 3.2" 0.3" 💧 Light watering
Aug 3.5" 3.7" 0" ✅ Rainfall sufficient
Sep 3.5" 2.8" 0.7" 💧 Light watering
Oct 3.5" 1.9" 1.6" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ellis 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 ~921 GDD — county provides 3,165 GDD Excellent fit

Chard Planting Timeline — Ellis County, OK

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 13 Aug 13 – Aug 27

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · 1-2 times/week

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

189 days in Ellis County

Growing Tips for Chard in Ellis County

Direct sow Chard outdoors after April 16 in Ellis 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 Ellis County, OK?

Ellis County is in Zone 7a 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 Ellis County, OK?

Ellis County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 16 and first fall frost is October 22.

🌱

Your Ellis County Garden Planner — Free

A 24-page printable planner built for Ellis 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 Ellis 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.