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When to Plant Celosia in Edmonton, AB

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.

Edmonton, Alberta is in USDA Zone 4b. The average last spring frost is May 13 and the first fall frost is October 7, giving you a growing season of approximately 147 days.

At an elevation of 2,191 feet, Edmonton receives approximately 17.4 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 70°F, so choose short-season varieties of Celosia to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Celosia successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Edmonton, AB (Zone 4b) Short season
147 days
Last Spring Frost May 13
147 growing days
First Fall Frost October 7
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Edmonton Soil Profile

Soil Type

Dark Brown Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Celosia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🌸 Bloom: Jul 1 – Sep 16
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🌸 Bloom: Jul 1 – Sep 16
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🌸 Bloom: Jul 1 – Sep 16

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
0.5″/week
Watering frequency Only during dry spells
Season total 4 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 2.2" 1.9" 0.3" 💧 Light watering
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 2" 0.2" 💧 Light watering
Aug 2.2" 2.1" 0.1" 💧 Light watering
Sep 2.2" 1.3" 0.9" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Edmonton). 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 ~188 GDD — county provides 367 GDD Excellent fit

Celosia Planting Timeline — Edmonton, AB

Celosia Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 27 May 27 – Jun 17
Bloom July 29 Jul 29 – Oct 14

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

Month-by-Month Timeline

MonthActivities
January
February
March
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 · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

147 days in Edmonton

Growing Tips for Celosia in Edmonton

Edmonton receives only 17" of rain annually. Celosia needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Edmonton, AB?

Edmonton is in Zone 4b with an average last frost of May 13. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Edmonton, AB?

Edmonton, Alberta is in USDA Hardiness Zone 4b. The average last spring frost is May 13 and first fall frost is October 7.

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Your Edmonton Garden Planner — Free

A 22-page printable planner built for Edmonton (Zone 4b). 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 Edmonton, AB. Local conditions may vary. Last updated: June 2026.

Sources & credits

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