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When to Plant Lettuce in Red Lake County, MN

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.

Red Lake County, Minnesota is in USDA Zone 3b. The average last spring frost is May 11 and the first fall frost is October 1, giving you a growing season of approximately 143 days.

At an elevation of 616 feet, Red Lake County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Lettuce to ensure they mature before fall.

Red Lake County, MN (Zone 3b) Short season
143 days
Last Spring Frost May 11
143 growing days
First Fall Frost October 1

Red Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Mar 21 Transplant: May 2 🍅 Harvest: Jun 6 – Aug 15
Recommended (50%) ✓ Fits season (38 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 24
Safe Start (90%) ✓ Fits season (40 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 Red Lake County

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

Soil pH

Your soil pH (6.1โ€“6.8) is within Lettuce's preferred range (6.0โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). 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 143-day season

Sow every 3.4 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Jul 09.

Plant Water Budget

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

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€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr โ€” 3.9" 0" โ„๏ธ Dormant
May 3" 3.6" 0" โœ… Rainfall sufficient
Jun 3" 4" 0" โœ… Rainfall sufficient
Jul 3" 4.4" 0" โœ… Rainfall sufficient
Aug 3" 4.3" 0" โœ… Rainfall sufficient
Sep 3" 3" 0" โœ… Rainfall sufficient
Oct 3" 2.8" 0.2" ๐Ÿ’ง Light watering
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Red Lake 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 ~450 GDD — county provides 1,430 GDD Excellent fit

Lettuce Planting Timeline โ€” Red Lake County, MN

Lettuce Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 โ€“ Apr 13
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Harvest June 15 Jun 15 โ€“ Aug 24
Fall Sowing July 9 Jul 9 โ€“ Jul 23

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: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 3b

๐Ÿ“† Growing Season

143 days in Red Lake County

Growing Tips for Lettuce in Red Lake County

Direct sow Lettuce outdoors after May 11 in Red Lake 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 Red Lake County, MN?

Red Lake County is in Zone 3b with an average last frost of May 11. Plan your Lettuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Red Lake County, MN?

Red Lake County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 11 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Red Lake County gardeners in Zone 3b 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 Red Lake County, MN. Local conditions may vary. Last updated: April 2026.