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When to Plant Celtuce in Lethbridge, AB

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.

Lethbridge, Alberta is in USDA Zone 5a. The average last spring frost is May 5 and the first fall frost is October 12, giving you a growing season of approximately 160 days.

At an elevation of 2,985 feet, Lethbridge receives approximately 23.7 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 74ยฐF, so choose short-season varieties of Celtuce to ensure they mature before fall.

Lethbridge, AB (Zone 5a) Moderate season
160 days
Last Spring Frost May 5
160 growing days
First Fall Frost October 12

Lethbridge Soil Profile

Soil Type

Dark Brown Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29

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.

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.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 111 gal / 100 sq ft

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€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 3" 3.1" 0" โœ… Rainfall sufficient
Jun 3" 2.8" 0.2" ๐Ÿ’ง Light watering
Jul 3" 2.4" 0.6" ๐Ÿ’ง Light watering
Aug 3" 2.3" 0.7" ๐Ÿ’ง Light watering
Sep 3" 2.1" 0.9" ๐Ÿ’ง Light watering
Oct 3" 2.1" 0.9" ๐Ÿ’ง Light watering
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Lethbridge). 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 ~412 GDD — county provides 880 GDD Excellent fit

Celtuce Planting Timeline โ€” Lethbridge, AB

Celtuce Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors May 5 May 5 โ€“ May 19
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest July 7 Jul 7 โ€“ Aug 18
Fall Sowing August 3 Aug 3 โ€“ Aug 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
August Fall Sowing Harvest
September โ€”
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: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

160 days in Lethbridge

Growing Tips for Celtuce in Lethbridge

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 Lethbridge, AB?

Lethbridge is in Zone 5a with an average last frost of May 5. Plan your Celtuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lethbridge, AB?

Lethbridge, Alberta is in USDA Hardiness Zone 5a. The average last spring frost is May 5 and first fall frost is October 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lethbridge gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Lethbridge, AB. Local conditions may vary. Last updated: April 2026.