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When to Plant Borage in Brandon, MB

Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.

Brandon, Manitoba is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is October 2, giving you a growing season of approximately 140 days.

At an elevation of 1,341 feet, Brandon receives approximately 15 inches of rainfall annually with predominantly black chernozem soil. Summer highs average 69°F, so choose short-season varieties of Borage to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Borage successfully. Mulch heavily to conserve soil moisture.

Brandon, MB (Zone 4a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2
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Brandon Soil Profile

Soil Type

Black Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Borage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 22
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 22
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 22

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 Borage

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Borage Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 62 gal / 100 sq ft

Monthly Watering Guide for Borage

Borage 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 Borage Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 2.2" 1.8" 0.4" 💧 Light watering
Jun 2.2" 1.9" 0.3" 💧 Light watering
Jul 2.2" 1.5" 0.7" 💧 Light watering
Aug 2.2" 1.6" 0.6" 💧 Light watering
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

Borage 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.

Borage needs ~96 GDD — county provides 245 GDD Excellent fit

Borage Planting Timeline — Brandon, MB

Borage Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 8 May 8 – May 29
Harvest July 3 Jul 3 – Aug 21
Fall Sowing July 10 Jul 10 – Jul 24

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Harvest
September
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

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

140 days in Brandon

Growing Tips for Brandon

Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Borage in Brandon, MB?

Brandon is in Zone 4a with an average last frost of May 15. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Brandon, MB?

Brandon, Manitoba is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is October 2.

🌱

Your Brandon Garden Planner — Free

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

Sources & credits

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