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When to Plant Celtuce in Franklin County, ID

Franklin County, Idaho Zone 6a May

Your May game plan for Franklin County, Idaho

May is a pivotal month for Franklin County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 19
Avg. first frost October 3
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Time to transplant celtuce

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Direct-sow celtuce

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Coming up in June — start thinking about
  • Starting indoors: celtuce

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Celtuce (stem lettuce) is a Chinese vegetable grown for its thick, crunchy stem rather than its leaves. The peeled stem has a mild, cucumber-like flavor.

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 Celtuce during the growing season. With low rainfall, drip irrigation is essential for growing Celtuce 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

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Jul 8 – Aug 19
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jul 21 – Sep 1
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Aug 15 – Sep 26

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 Franklin County

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

Soil pH

Your soil pH (6.7–7.7) is more alkaline than Celtuce prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Franklin County is excellent for Celtuce — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Celtuce.

How to Plant Celtuce

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Celtuce

2
successive plantings in your 137-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 25.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 194 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Celtuce

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

Month Celtuce 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 3" 1.9" 1.1" 💧 Light watering
Jun 3" 1.3" 1.7" 🚿 Regular watering
Jul 3" 1.8" 1.2" 💧 Light watering
Aug 3" 2" 1" 💧 Light watering
Sep 3" 1.6" 1.4" 💧 Light watering
Oct 3" 1.8" 1.2" 💧 Light 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.

Celtuce 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" — every day above 50°F 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.

Celtuce needs ~1,144 GDD — county provides 2,089 GDD Excellent fit

Celtuce Planting Timeline — Franklin County, ID

Celtuce 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 July 21 Jul 21 – 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
July Fall Sowing Harvest
August Fall Sowing Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

137 days in Franklin County

Growing Tips for Celtuce in Franklin County

Direct sow Celtuce outdoors after May 19 in Franklin County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow in spring or start indoors. Space 12 inches apart. Harvest when stems are about 1 inch in diameter. Peel the tough outer skin to reveal the tender center.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celtuce in Franklin County, ID?

Franklin County is in Zone 6a with an average last frost of May 19. Plan your Celtuce 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.

🌱

Your Franklin County Garden Planner — Free

A 24-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.

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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: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.