Blog

When to Plant Radicchio in Kenora, ON

Radicchio is an Italian chicory with stunning red and white leaves and a pleasantly bitter flavor. It forms tight heads and is used in salads, grilled, or braised.

Kenora, Ontario 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 1,069 feet, Kenora receives approximately 19.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 73°F, so choose short-season varieties of Radicchio to ensure they mature before fall. Clay soil retains moisture well for Radicchio, but amend with compost to improve drainage and prevent root rot. With low rainfall, drip irrigation is essential for growing Radicchio successfully. Mulch heavily to conserve soil moisture.

Kenora, ON (Zone 4a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2
Share this guide:

Kenora 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 (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 22
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 22
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 4 Transplant: Apr 15 🍅 Harvest: Jun 17 – 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 Radicchio

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 155 gal / 100 sq ft

Monthly Watering Guide for Radicchio

Radicchio needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Radicchio Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 3" 2.4" 0.6" 💧 Light watering
Jun 3" 2.1" 0.9" 💧 Light watering
Jul 3" 2.4" 0.6" 💧 Light watering
Aug 3" 1.9" 1.1" 💧 Light watering
Sep 3" 1.5" 1.5" 🚿 Regular watering
Oct 3" 1.4" 1.6" 🚿 Regular watering
Nov 1.5" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

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

Radicchio 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.

Radicchio needs ~332 GDD — county provides 665 GDD Excellent fit

Radicchio Planting Timeline — Kenora, ON

Radicchio Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 17 Jul 17 – Aug 21
Fall Sowing July 10 Jul 10 – Jul 24

Plant 0.5" deep · 6" 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
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

140 days in Kenora

Growing Tips for Radicchio in Kenora

Common pests for Radicchio in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start in late summer for fall harvest. The red color develops with cool nights and light frost. Harvest when heads are firm and compact.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radicchio in Kenora, ON?

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

What planting zone is Kenora, ON?

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

🌱

Your Kenora Garden Planner — Free

A 24-page printable planner built for Kenora (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 Kenora, ON. Local conditions may vary. Last updated: May 2026.

Sources & credits

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