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When to Plant Celtuce in Granite County, MT

Granite County, Montana Zone 5a May

May in the garden — Granite County, Montana

Your garden in Granite County, Montana is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 29
Avg. first frost September 20
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
  1. Get celtuce in the ground

    Your last frost (May 29) has passed. These warm-season crops can handle outdoor soil now.

  2. Sow celtuce where they'll grow

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

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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.

Granite County, Montana is in USDA Zone 5a. The average last spring frost is May 29 and the first fall frost is September 20, giving you a growing season of approximately 114 days.

At an elevation of 7,177 feet, Granite County receives approximately 18.9 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Celtuce to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Celtuce successfully. Mulch heavily to conserve soil moisture.

Granite County, MT (Zone 5a) Short season
114 days
Last Spring Frost May 29
114 growing days
First Fall Frost September 20
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Granite County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Jul 20 – Aug 31
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 24 Transplant: May 29 🍅 Harvest: Jul 31 – Sep 11
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: May 16 Transplant: Jun 20 🍅 Harvest: Aug 22 – Oct 3

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 Granite County

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

Soil pH

Your soil pH (6.6–7.6) is more alkaline than Celtuce prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Granite 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 114-day season

Sow every 6.9 weeks. Last sowing by Jun 22 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
Watering frequency Only during dry spells
Season total 4 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 1.4" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 3" 2.5" 0.5" 💧 Light watering
Jun 3" 1.4" 1.6" 🚿 Regular watering
Jul 3" 1.5" 1.5" 🚿 Regular watering
Aug 3" 2" 1" 💧 Light watering
Sep 3" 1.7" 1.3" 💧 Light watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Granite 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 ~806 GDD — county provides 1,225 GDD Excellent fit

Celtuce Planting Timeline — Granite County, MT

Celtuce Planting Calendar

Activity When Date Range
Start Indoors April 24 Apr 24 – May 8
Transplant Outdoors May 29 May 29 – Jun 12
Direct Sow May 15 May 15 – Jun 5
Harvest July 31 Jul 31 – Sep 11
Fall Sowing July 12 Jul 12 – Jul 26

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December
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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 5a

📆 Growing Season

114 days in Granite County

Growing Tips for Celtuce in Granite County

Direct sow Celtuce outdoors after May 29 in Granite 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 Granite County, MT?

Granite County is in Zone 5a with an average last frost of May 29. Plan your Celtuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is Granite County, MT?

Granite County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is May 29 and first fall frost is September 20.

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Your Granite County Garden Planner — Free

A 24-page printable planner built for Granite County (Zone 5a). 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 Granite County, MT. 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.