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When to Plant Cress in Peterborough, ON

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.

Peterborough, Ontario is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 17, giving you a growing season of approximately 187 days.

At an elevation of 656 feet, Peterborough receives approximately 40.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Cress to ensure they mature before fall. Clay soil retains moisture well for Cress, but amend with compost to improve drainage and prevent root rot.

Peterborough, ON (Zone 6b) Moderate season
187 days
Last Spring Frost April 13
187 growing days
First Fall Frost October 17

Peterborough Soil Profile

Soil Type

Clay Loam

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 11 Transplant: Apr 15 🍅 Harvest: Apr 29 – May 20
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Apr 29 – May 20
Safe Start (90%) ✓ Fits season (148 days to spare)
Start indoors: Mar 11 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 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 147 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€” 1.9" 0" โ„๏ธ Dormant
Feb โ€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr 4.3" 4.3" 0" โœ… Rainfall sufficient
May 4.3" 4.5" 0" โœ… Rainfall sufficient
Jun 4.3" 5.1" 0" โœ… Rainfall sufficient
Jul 4.3" 5" 0" โœ… Rainfall sufficient
Aug 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Sep 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Peterborough). 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 ~188 GDD — county provides 2,010 GDD Excellent fit

Cress Planting Timeline โ€” Peterborough, ON

Cress Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 โ€“ Mar 23
Transplant Outdoors April 13 Apr 13 โ€“ Apr 27
Direct Sow March 30 Mar 30 โ€“ Apr 20
Harvest April 27 Apr 27 โ€“ May 18
Fall Sowing August 8 Aug 8 โ€“ Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

14โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

187 days in Peterborough

Growing Tips for Cress in Peterborough

Your generous 187.0-day season in Peterborough 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.

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 Peterborough, ON?

Peterborough is in Zone 6b with an average last frost of April 13. Plan your Cress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Peterborough, ON?

Peterborough, Ontario is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Peterborough gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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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 Peterborough, ON. Local conditions may vary. Last updated: April 2026.