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When to Plant Celtuce in Greater Sudbury, ON

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.

Greater Sudbury, Ontario is in USDA Zone 5b. The average last spring frost is April 24 and the first fall frost is October 8, giving you a growing season of approximately 167 days.

At an elevation of 1,141 feet, Greater Sudbury receives approximately 29.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 77ยฐF, so choose short-season varieties of Celtuce to ensure they mature before fall. Clay soil retains moisture well for Celtuce, but amend with compost to improve drainage and prevent root rot.

Greater Sudbury, ON (Zone 5b) Moderate season
167 days
Last Spring Frost April 24
167 growing days
First Fall Frost October 8

Greater Sudbury Soil Profile

Soil Type

Clay Loam

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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 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€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.3" 0" โ„๏ธ Dormant
Apr 3" 2.9" 0.1" ๐Ÿ’ง Light watering
May 3" 3.8" 0" โœ… Rainfall sufficient
Jun 3" 3.5" 0" โœ… Rainfall sufficient
Jul 3" 3.4" 0" โœ… Rainfall sufficient
Aug 3" 3" 0" โœ… Rainfall sufficient
Sep 3" 2.7" 0.3" ๐Ÿ’ง Light watering
Oct 3" 2" 1" ๐Ÿ’ง Light watering
Nov โ€” 1.8" 0" โ„๏ธ Dormant
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Greater Sudbury). 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 ~581 GDD — county provides 1,294 GDD Excellent fit

Celtuce Planting Timeline โ€” Greater Sudbury, ON

Celtuce Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 โ€“ Apr 3
Transplant Outdoors April 24 Apr 24 โ€“ May 8
Direct Sow April 10 Apr 10 โ€“ May 1
Harvest June 26 Jun 26 โ€“ Aug 7
Fall Sowing July 30 Jul 30 โ€“ Aug 13

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 Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing 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 Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

167 days in Greater Sudbury

Growing Tips for Celtuce in Greater Sudbury

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 Greater Sudbury, ON?

Greater Sudbury is in Zone 5b with an average last frost of April 24. Plan your Celtuce planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Greater Sudbury, ON?

Greater Sudbury, Ontario is in USDA Hardiness Zone 5b. The average last spring frost is April 24 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Greater Sudbury gardeners in Zone 5b 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 Greater Sudbury, ON. Local conditions may vary. Last updated: April 2026.