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When to plant Lettuce in Franklin County, ID

In Franklin County, plant Lettuce in spring between May 5 and May 26, once soil temps hold above 50°F. Franklin County's last frost averages May 19, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between July 25 and August 8 — roughly 30–60 days before the first frost on October 3.

When to Plant Lettuce in Franklin County, ID

Lettuce

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.

Franklin County, Idaho is in USDA Zone 6a. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.

At an elevation of 7,665 feet, Franklin County receives approximately 18.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lettuce during the growing season. With low rainfall, drip irrigation is essential for growing Lettuce successfully. Mulch heavily to conserve soil moisture.

Franklin County, ID (Zone 6a) Short season
137 days
Last Spring Frost May 19
137 growing days
First Fall Frost October 3

Franklin County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

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 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 1.9" 2.4" 🚿 Regular watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2" 2.3" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Franklin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lettuce Planting Timeline — Franklin County, ID

Lettuce Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 5 May 5 – May 26
Harvest June 23 Jun 23 – Sep 1
Fall Sowing July 25 Jul 25 – Aug 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

30–60 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

137 days in Franklin County

Growing Tips for Franklin 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 →

🌾 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 35°F, under 45% humidity.

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

Frequently Asked Questions

When should I plant Lettuce in Franklin County, ID?

Franklin County is in Zone 6a with an average last frost of May 19. Plan your Lettuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, ID?

Franklin County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 19 and first fall frost is October 3.

When should I plant Lettuce in Franklin County, ID?

In Franklin County, ID, plant Lettuce after the last frost (around May 19) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Franklin County, ID for Lettuce?

Franklin County sits in USDA Zone 6a. Lettuce grows reliably in zones 2a through 11b, so it's a good fit here.

Can Lettuce grow in Franklin County's climate?

Yes — Lettuce grows well in Franklin County's temperate climate. Franklin County averages a 137-day frost-free season, with last frost around May 19 and first frost around October 3.

🌱

Your Franklin County Garden Planner — Free

A 22-page printable planner built for Franklin County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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