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When to Plant Lettuce in Thomas County, NE

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.

Thomas County, Nebraska is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 5, giving you a growing season of approximately 148 days.

At an elevation of 1,062 feet, Thomas County receives approximately 31.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Lettuce to ensure they mature before fall.

Thomas County, NE (Zone 4b) Short season
148 days
Last Spring Frost May 10
148 growing days
First Fall Frost October 5

Thomas County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Mar 23 Transplant: May 4 🍅 Harvest: Jun 8 – Aug 17
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jun 14 – Aug 23
Safe Start (90%) ✓ Fits season (41 days to spare)
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Jun 26 – Sep 4

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 Thomas County

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

Soil pH

Your soil pH (6.2โ€“7.4) overlaps with Lettuce's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Thomas County is excellent for Lettuce โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Lettuce.

How to Plant Lettuce

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Lettuce

5
successive plantings in your 148-day season

Sow every 3.4 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Lettuce

Lettuce needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Lettuce Needs Rainfall You Supplement Action
Jan โ€” 2" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 3" 0" โ„๏ธ Dormant
Apr โ€” 3.1" 0" โ„๏ธ Dormant
May 3" 3.3" 0" โœ… Rainfall sufficient
Jun 3" 2.1" 0.9" ๐Ÿ’ง Light watering
Jul 3" 2.9" 0.1" ๐Ÿ’ง Light watering
Aug 3" 3.8" 0" โœ… Rainfall sufficient
Sep 3" 2.4" 0.6" ๐Ÿ’ง Light watering
Oct 3" 2.5" 0.5" ๐Ÿ’ง Light watering
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Thomas County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Lettuce 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" โ€” every day above 50ยฐF 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.

Lettuce needs ~585 GDD — county provides 1,924 GDD Excellent fit

Lettuce Planting Timeline โ€” Thomas County, NE

Lettuce Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 โ€“ Apr 12
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow May 3 May 3 โ€“ May 24
Harvest June 14 Jun 14 โ€“ Aug 23
Fall Sowing July 13 Jul 13 โ€“ Jul 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

30โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

148 days in Thomas County

Growing Tips for Lettuce in Thomas County

Direct sow Lettuce outdoors after May 10 in Thomas County when soil has warmed and frost danger has passed.

Common pests for Lettuce in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

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 Thomas County, NE?

Thomas County is in Zone 4b with an average last frost of May 10. Plan your Lettuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Thomas County, NE?

Thomas County, Nebraska is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Thomas County gardeners in Zone 4b 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 Thomas County, NE. Local conditions may vary. Last updated: April 2026.