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When to Plant Celtuce in Grand County, CO

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.

Grand County, Colorado is in USDA Zone 4a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.

At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Celtuce to ensure they mature before fall.

Grand County, CO (Zone 4a) Short season
114 days
Last Spring Frost May 28
114 growing days
First Fall Frost September 19

Grand County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Jul 15 – Aug 26
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 16 Transplant: May 28 🍅 Harvest: Jul 30 – Sep 10
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: May 7 Transplant: Jun 18 🍅 Harvest: Aug 20 – Oct 1

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 Grand County

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

Soil pH

Your soil pH (6.7โ€“8.3) is more alkaline than Celtuce prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Grand County is excellent for Celtuce โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Celtuce.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Celtuce.

How to Plant Celtuce

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

Fall planting: Sow 12 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 21 to harvest before frost.

For a dedicated fall crop, sow by Jun 27.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 112 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.9" 0" โ„๏ธ Dormant
Apr โ€” 2.1" 0" โ„๏ธ Dormant
May 3" 3" 0" โœ… Rainfall sufficient
Jun 3" 1.5" 1.5" ๐Ÿšฟ Regular watering
Jul 3" 2" 1" ๐Ÿ’ง Light watering
Aug 3" 2.3" 0.7" ๐Ÿ’ง Light watering
Sep 3" 1.6" 1.4" ๐Ÿ’ง Light watering
Oct โ€” 2.2" 0" โ„๏ธ Dormant
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Grand County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 1,311 GDD Excellent fit

Celtuce Planting Timeline โ€” Grand County, CO

Celtuce Planting Calendar

Activity When Date Range
Start Indoors April 16 Apr 16 โ€“ Apr 30
Transplant Outdoors May 28 May 28 โ€“ Jun 11
Direct Sow May 21 May 21 โ€“ Jun 11
Harvest July 30 Jul 30 โ€“ Sep 10
Fall Sowing June 27 Jun 27 โ€“ Jul 11

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 Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow Fall Sowing
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

114 days in Grand County

Growing Tips for Celtuce in Grand County

Direct sow Celtuce outdoors after May 28 in Grand 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 Grand County, CO?

Grand County is in Zone 4a with an average last frost of May 28. Plan your Celtuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grand County, CO?

Grand County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is May 28 and first fall frost is September 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grand County gardeners in Zone 4a 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 Grand County, CO. Local conditions may vary. Last updated: April 2026.