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When to Plant Calendula in Dauphin, MB

Calendula (Calendula officinalis) is a cheerful, edible-flowered cool-season annual valued by herbalists, chefs, and gardeners alike. Its golden-orange petals are used in salves, teas, and as a saffron substitute. Hardy enough to tolerate light frosts, it blooms prolifically in spring and fall, taking a pause during the hottest weeks of summer.

Dauphin, Manitoba is in USDA Zone 4a. The average last spring frost is May 17 and the first fall frost is October 4, giving you a growing season of approximately 140 days.

At an elevation of 1,000 feet, Dauphin receives approximately 12 inches of rainfall annually with predominantly black chernozem soil. Summer highs average 74°F, so choose short-season varieties of Calendula to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Calendula successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Dauphin, MB (Zone 4a) Short season
140 days
Last Spring Frost May 17
140 growing days
First Fall Frost October 4
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Dauphin Soil Profile

Soil Type

Black Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Calendula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Start indoors: Feb 25 Transplant: Apr 15 🌸 Bloom: Jun 3 – Aug 19
Recommended (50%) ✓ Fits season (57 days to spare)
Start indoors: Feb 25 Transplant: Apr 15 🌸 Bloom: Jun 3 – Aug 19
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Feb 25 Transplant: Apr 15 🌸 Bloom: Jun 3 – Aug 19

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 Calendula

0.3"
Planting Depth
9"
Between Plants
12"
Between Rows

Calendula Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 174 gal / 100 sq ft

Monthly Watering Guide for Calendula

Calendula 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 Calendula Needs Rainfall You Supplement Action
Jan 0.4" 0" ❄️ Dormant
Feb 0.5" 0" ❄️ Dormant
Mar 0.7" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 2.2" 1.5" 0.7" 💧 Light watering
Jun 2.2" 1.5" 0.7" 💧 Light watering
Jul 2.2" 1.2" 1" 💧 Light watering
Aug 2.2" 1.4" 0.8" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light watering
Oct 2.2" 1" 1.2" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

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

Calendula 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.

Calendula needs ~330 GDD — county provides 770 GDD Excellent fit

Calendula Planting Timeline — Dauphin, MB

Calendula Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 3 May 3 – May 24
Bloom July 5 Jul 5 – Sep 20

Plant 0.3" 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
July Bloom
August Bloom
September Bloom
October
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

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

140 days in Dauphin

Growing Tips for Calendula in Dauphin

Common pests for Calendula in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Dauphin receives only 12" of rain annually. Calendula needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct-sow in early spring as soon as soil can be worked — seeds germinate in cool soil (50-65°F). In zones 7+, also sow in fall for winter/spring bloom. Deadhead consistently to extend bloom. Plants self-seed readily; save a few spent heads and allow them to drop. Harvest petals when flowers are fully open for best flavor and medicinal value.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Calendula in Dauphin, MB?

Dauphin is in Zone 4a with an average last frost of May 17. Plan your Calendula planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dauphin, MB?

Dauphin, Manitoba is in USDA Hardiness Zone 4a. The average last spring frost is May 17 and first fall frost is October 4.

🌱

Your Dauphin Garden Planner — Free

A 22-page printable planner built for Dauphin (Zone 4a). 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 Dauphin, MB. Local conditions may vary. Last updated: June 2026.

Sources & credits

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