Blog

When to Plant Cress in Edmonton, AB

Garden cress is one of the fastest-growing edibles, producing peppery sprouts in as little as two weeks. It is excellent for microgreens and garnishes.

Edmonton, Alberta is in USDA Zone 4b. The average last spring frost is May 13 and the first fall frost is October 7, giving you a growing season of approximately 147 days.

At an elevation of 2,191 feet, Edmonton receives approximately 17.4 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 70ยฐF, so choose short-season varieties of Cress to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cress successfully. Mulch heavily to conserve soil moisture.

Edmonton, AB (Zone 4b) Short season
147 days
Last Spring Frost May 13
147 growing days
First Fall Frost October 7

Edmonton 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 (148 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Apr 29 – May 20
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Apr 29 – May 20
Safe Start (90%) ✓ Fits season (148 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Apr 29 – May 20

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 Cress

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 658 gal / 100 sq ft

Monthly Watering Guide for Cress

Cress needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cress Needs Rainfall You Supplement Action
Jan โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr โ€” 1.6" 0" โ„๏ธ Dormant
May 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Jun 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Jul 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Aug 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Sep 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Oct 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Nov โ€” 1.2" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Edmonton). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cress 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.

Cress needs ~44 GDD — county provides 367 GDD Excellent fit

Cress Planting Timeline โ€” Edmonton, AB

Cress Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 โ€“ Apr 15
Transplant Outdoors May 13 May 13 โ€“ May 27
Direct Sow May 6 May 6 โ€“ May 27
Harvest May 27 May 27 โ€“ Jun 17
Fall Sowing July 15 Jul 15 โ€“ Jul 29

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

14โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

147 days in Edmonton

Growing Tips for Cress in Edmonton

Your generous 147.0-day season in Edmonton allows multiple plantings of Cress. Sow every 7.0 days for continuous harvest.

Common pests for Cress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Edmonton receives only 17" of rain annually. Cress needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Sow seeds thickly on moist soil or paper towels. Keep moist and harvest when 2-3 inches tall. Succession sow every few days for continuous supply. Grows well indoors year-round.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cress in Edmonton, AB?

Edmonton is in Zone 4b with an average last frost of May 13. Plan your Cress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Edmonton, AB?

Edmonton, Alberta is in USDA Hardiness Zone 4b. The average last spring frost is May 13 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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 Edmonton, AB. Local conditions may vary. Last updated: April 2026.