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When to Plant Borage in Banff-Jasper, AB

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.

Banff-Jasper, Alberta 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 4,537 feet, Banff-Jasper receives approximately 20.6 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 70ยฐF, so choose short-season varieties of Borage to ensure they mature before fall.

Banff-Jasper, AB (Zone 4a) Short season
140 days
Last Spring Frost May 17
140 growing days
First Fall Frost October 4

Banff-Jasper Soil Profile

Soil Type

Dark Brown Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Plant 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr โ€” 2" 0" โ„๏ธ Dormant
May 2.2" 2.5" 0" โœ… Rainfall sufficient
Jun 2.2" 2.3" 0" โœ… Rainfall sufficient
Jul 2.2" 2.5" 0" โœ… Rainfall sufficient
Aug 2.2" 2.4" 0" โœ… Rainfall sufficient
Sep 2.2" 2" 0.2" ๐Ÿ’ง Light watering
Oct 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Banff-Jasper). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~138 GDD — county provides 350 GDD Excellent fit

Borage Planting Timeline โ€” Banff-Jasper, AB

Borage Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 โ€“ Apr 19
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow May 10 May 10 โ€“ May 31
Harvest July 5 Jul 5 โ€“ Aug 23
Fall Sowing July 12 Jul 12 โ€“ Jul 26

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

140 days in Banff-Jasper

Growing Tips for Banff-Jasper

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 Banff-Jasper, AB?

Banff-Jasper is in Zone 4a with an average last frost of May 17. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Banff-Jasper, AB?

Banff-Jasper, Alberta is in USDA Hardiness Zone 4a. The average last spring frost is May 17 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Banff-Jasper gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

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