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When to Plant Lettuce in Carter County, OK

Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.

Carter County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 648 feet, Carter County receives approximately 34.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Lettuce during the growing season.

Carter County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Carter County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (116 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: Apr 25 – Jul 4
Recommended (50%) ✓ Fits season (114 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 2 – Jul 11
Safe Start (90%) ✓ Fits season (115 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,507 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Lettuce needs ~889 GDD — county provides 4,325 GDD Excellent fit

Lettuce Planting Timeline โ€” Carter County, OK

Lettuce Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 โ€“ Mar 7
Transplant Outdoors March 28 Mar 28 โ€“ Apr 11
Direct Sow March 14 Mar 14 โ€“ Apr 4
Fall Sowing August 24 Aug 24 โ€“ Sep 7
Harvest May 2 May 2 โ€“ Jul 11

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7b

Growing Season

219 days

Growing Tips for Carter County

Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.

Companion Planting

Good Companions

Avoid Planting Near

  • Celery

Level Up Your Garden

๐ŸŒพ Save Your Own Lettuce Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let plants bolt and flower. Harvest seed heads when fluffy.
Storage Store airtight; viable 6 years at 35ยฐF, under 45% humidity.

Very easy to save. Let a few plants bolt each season.

Frequently Asked Questions

When should I plant Lettuce in Carter County, OK?

Carter County is in Zone 7b with an average last frost of March 28. Plan your Lettuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Carter County, OK?

Carter County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 28 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Carter County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Carter County, OK. Local conditions may vary. Last updated: April 2026.