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When to Plant Lemon Balm in Grande Prairie, AB

Lemon balm is a vigorous perennial herb with bright green, lemon-scented leaves. It makes a refreshing tea and is easy to grow but can spread aggressively.

Grande Prairie, Alberta is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is October 9, giving you a growing season of approximately 140 days.

At an elevation of 2,194 feet, Grande Prairie receives approximately 19 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 75°F, so choose short-season varieties of Lemon Balm to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Lemon Balm successfully. Mulch heavily to conserve soil moisture.

Grande Prairie, AB (Zone 4a) Short season
140 days
Last Spring Frost May 22
140 growing days
First Fall Frost October 9

Grande Prairie Soil Profile

Soil Type

Dark Brown Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Lemon Balm Planting Timeline — Grande Prairie, AB

Lemon Balm Planting Calendar

Activity When Date Range
Transplant Outdoors May 29 May 29 – Jun 12
Harvest July 31 Jul 31 – Sep 18

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

140 days in Grande Prairie

Growing Tips for Grande Prairie

Start from seed, cuttings, or divisions. Contain in pots or use barriers to prevent spreading. Harvest frequently to keep plants bushy and prevent flowering.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemon Balm in Grande Prairie, AB?

Grande Prairie is in Zone 4a with an average last frost of May 22. Plan your Lemon Balm planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grande Prairie, AB?

Grande Prairie, Alberta is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is October 9.

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Your Grande Prairie Garden Planner — Free

A 22-page printable planner built for Grande Prairie (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 Grande Prairie, AB. Local conditions may vary. Last updated: July 2026.

Sources & credits

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