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When to Plant Celosia in Rimouski, QC

Celosia (Celosia argentea) encompasses the vivid cockscomb (cristata) and feathery plumed (plumosa) types that explode with color in summer heat. Drought-tolerant and disease-resistant, they thrive in the hottest parts of the season and produce long-lasting blooms both in the garden and as cut or dried flowers. A reliable filler in sunny annual beds.

Rimouski, Quebec is in USDA Zone 5a. The average last spring frost is May 4 and the first fall frost is October 11, giving you a growing season of approximately 160 days.

At an elevation of 114 feet, Rimouski receives approximately 31.2 inches of rainfall annually with predominantly gray-brown podzol soil. Summer highs average 73°F, so choose short-season varieties of Celosia to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Rimouski, QC (Zone 5a) Moderate season
160 days
Last Spring Frost May 4
160 growing days
First Fall Frost October 11
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Rimouski Soil Profile

Soil Type

Gray-Brown Podzol

Soil pH

6.0-7.0

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🌸 Bloom: Jul 1 – Sep 30
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🌸 Bloom: Jul 1 – Sep 30
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🌸 Bloom: Jul 1 – Sep 30

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 Celosia

0.1"
Planting Depth
9"
Between Plants
12"
Between Rows

Celosia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Celosia

Celosia needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Celosia Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 2.2" 3.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Rimouski). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Celosia 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.

Celosia needs ~356 GDD — county provides 760 GDD Excellent fit

Celosia Planting Timeline — Rimouski, QC

Celosia Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors May 18 May 18 – Jun 1
Direct Sow May 18 May 18 – Jun 8
Bloom July 20 Jul 20 – Oct 19

Plant 0.1" deep · 9" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Bloom
August Bloom
September Bloom
October Bloom
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

160 days in Rimouski

Growing Tips for Rimouski

Start seeds indoors 4–6 weeks before last frost, or direct-sow after soil warms above 60°F. Does not transplant well from large pots — sow in small cells or direct-sow. Needs full sun and warm soil; cold stress causes stunting. Pinch first bloom to encourage branching. Water at the base; wet foliage encourages fungal issues. Excellent dried flower — harvest before seeds set for the best color retention.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celosia in Rimouski, QC?

Rimouski is in Zone 5a with an average last frost of May 4. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rimouski, QC?

Rimouski, Quebec is in USDA Hardiness Zone 5a. The average last spring frost is May 4 and first fall frost is October 11.

🌱

Your Rimouski Garden Planner — Free

A 22-page printable planner built for Rimouski (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Rimouski, QC. Local conditions may vary. Last updated: June 2026.

Sources & credits

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