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When to plant Celtuce in Clark County, ID

Plant Celtuce in Clark County, when soil hits 50°F — usually May 24. Continue planting through June 14 for the spring crop. A second sowing from July 2 to July 16 extends the harvest into fall.

When to Plant Celtuce in Clark County, ID

Clark County, Idaho Zone 5b July

July in Clark County, Idaho — your action list

Your Clark County, Idaho garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost June 7
Avg. first frost September 10
Soil temp (4") 49°F
Watering High
Pest pressure High
Daylight 15 hrs
  1. Start celtuce under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Kick off the fall garden with celtuce

    A row cover ready in the garage extends your harvest by weeks once the nights turn cold.

Get ahead of August
  • First harvests: 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.

Clark County, Idaho is in USDA Zone 5b. The average last spring frost is June 7 and the first fall frost is September 10, giving you a growing season of approximately 95 days.

At an elevation of 7,493 feet, Clark County receives approximately 21.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Celtuce to ensure they mature before fall.

Clark County, ID (Zone 5b) Very short season
95 days
Last Spring Frost June 7
95 growing days
First Fall Frost September 10

Clark County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Celtuce Planting Risk Windows

Early Start (70% safe) ✓ Fits season (1 days to spare)
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: Jul 25 – Sep 5
Recommended (50%) ✗ May not fit
Start indoors: May 3 Transplant: Jun 7 🍅 Harvest: Aug 9 – Sep 20
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: May 17 Transplant: Jun 21 🍅 Harvest: Aug 23 – Oct 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 Clark County

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

Soil pH

Your soil pH (6.8–7.8) is more alkaline than Celtuce prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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.

Celtuce Water Budget

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

Water stress score is 6/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 2.5" 0" ❄️ Dormant
Jun 3" 1.5" 1.5" 🚿 Regular watering
Jul 3" 1.7" 1.3" 💧 Light watering
Aug 3" 2.2" 0.8" 💧 Light watering
Sep 3" 1.7" 1.3" 💧 Light watering
Oct 1.8" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Clark 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 ~862 GDD — county provides 1,092 GDD Good fit

Celtuce Planting Timeline — Clark County, ID

Celtuce Planting Calendar

Activity When Date Range
Start Indoors May 3 May 3 – May 17
Transplant Outdoors June 7 Jun 7 – Jun 21
Direct Sow May 24 May 24 – Jun 14
Harvest August 9 Aug 9 – Sep 20
Fall Sowing July 2 Jul 2 – Jul 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

95 days in Clark County

Growing Tips for Celtuce in Clark County

Direct sow Celtuce outdoors after June 07 in Clark County when soil has warmed and frost danger has passed.

Your 95.0-day growing season in Clark County is tight for Celtuce (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Clark County, ID?

Clark County is in Zone 5b with an average last frost of June 7. Plan your Celtuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, ID?

Clark County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is June 7 and first fall frost is September 10.

When should I plant Celtuce in Clark County, ID?

In Clark County, ID, plant Celtuce after the last frost (around June 7) and before the first frost (around September 10). Best results when soil holds above 50°F.

What growing zone is Clark County, ID for Celtuce?

Clark County sits in USDA Zone 5b. Celtuce grows reliably in zones 3a through 10b, so it's a good fit here.

Can Celtuce grow in Clark County's climate?

Yes — Celtuce grows well in Clark County's temperate climate. Clark County averages a 95-day frost-free season, with last frost around June 7 and first frost around September 10.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 5b). 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 Clark County, ID. Local conditions may vary. Last updated: July 2026.

Sources & credits

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