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When to Plant Lettuce in Bannock County, ID

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.

Bannock County, Idaho is in USDA Zone 5a. The average last spring frost is May 23 and the first fall frost is September 24, giving you a growing season of approximately 124 days.

At an elevation of 5,637 feet, Bannock County receives approximately 13.1 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Lettuce to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Lettuce successfully. Mulch heavily to conserve soil moisture.

Bannock County, ID (Zone 5a) Short season
124 days
Last Spring Frost May 23
124 growing days
First Fall Frost September 24

Bannock County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.1

Drainage

Well Drained

Monthly Watering Guide for Lettuce

Lettuce needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Lettuce Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr โ€” 1.4" 0" โ„๏ธ Dormant
May 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Jun 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Aug 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Sep 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Oct โ€” 1" 0" โ„๏ธ Dormant
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

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

Lettuce Planting Timeline โ€” Bannock County, ID

Lettuce Planting Calendar

Activity When Date Range
Start Indoors April 18 Apr 18 โ€“ May 2
Transplant Outdoors May 23 May 23 โ€“ Jun 6
Direct Sow May 9 May 9 โ€“ May 30
Harvest June 27 Jun 27 โ€“ Sep 5
Fall Sowing July 16 Jul 16 โ€“ Jul 30

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

30โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

124 days in Bannock County

Growing Tips for Bannock 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

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 Bannock County, ID?

Bannock County is in Zone 5a with an average last frost of May 23. Plan your Lettuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bannock County, ID?

Bannock County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 23 and first fall frost is September 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bannock County gardeners in Zone 5a 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 Bannock County, ID. Local conditions may vary. Last updated: April 2026.