Blog

When to Plant Celosia in Thompson, MB

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.

Thompson, Manitoba is in USDA Zone 3b. The average last spring frost is May 25 and the first fall frost is September 29, giving you a growing season of approximately 127 days.

At an elevation of 728 feet, Thompson receives approximately 11.2 inches of rainfall annually with predominantly black chernozem soil. Summer highs average 66°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
Thompson, MB (Zone 3b) Short season
127 days
Last Spring Frost May 25
127 growing days
First Fall Frost September 29

Thompson Soil Profile

Soil Type

Black Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Celosia Planting Timeline — Thompson, MB

Celosia Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 – Apr 27
Transplant Outdoors June 15 Jun 15 – Jun 29
Direct Sow June 15 Jun 15 – Jul 6
Bloom August 17 Aug 17 – Oct 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 3b

📆 Growing Season

127 days in Thompson

Growing Tips for Thompson

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 Thompson, MB?

Thompson is in Zone 3b with an average last frost of May 25. Plan your Celosia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Thompson, MB?

Thompson, Manitoba is in USDA Hardiness Zone 3b. The average last spring frost is May 25 and first fall frost is September 29.

🌱

Your Thompson Garden Planner — Free

A 22-page printable planner built for Thompson (Zone 3b). 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 Thompson, MB. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.