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When to Plant Radicchio in Dunn County, ND

Dunn County, North Dakota Zone 4a May

Top priorities for Dunn County, North Dakota gardeners in May

Your Dunn County, North Dakota garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 14
Avg. first frost September 23
Soil temp (4") 53°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Move radicchio from tray to bed

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Plant radicchio from seed, right in the garden

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

June will be here before you know it — start on
  • Starting indoors: radicchio

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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.

Dunn County, North Dakota is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 23, giving you a growing season of approximately 132 days.

At an elevation of 944 feet, Dunn County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Radicchio to ensure they mature before fall.

Dunn County, ND (Zone 4a) Short season
132 days
Last Spring Frost May 14
132 growing days
First Fall Frost September 23
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Dunn County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jul 12 – Aug 16
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Jul 16 – Aug 20
Safe Start (90%) ✓ Fits season (34 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Aug 1 – Sep 5

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.

Soil Compatibility in Dunn County

How your county's soil matches Radicchio's growing requirements.

Soil pH

Your soil pH (6.2–7.5) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Dunn County is excellent for Radicchio — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Radicchio.

Organic Matter

Organic matter is excellent (4.2%) — Radicchio will thrive.

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.

Succession Planting Radicchio

2
successive plantings in your 132-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 01.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 283 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 3" 2.5" 0.5" 💧 Light watering
Jun 3" 1.5" 1.5" 🚿 Regular watering
Jul 3" 1.9" 1.1" 💧 Light watering
Aug 3" 2.6" 0.4" 💧 Light watering
Sep 3" 1.9" 1.1" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Dunn County). 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 ~700 GDD — county provides 1,320 GDD Excellent fit

Radicchio Planting Timeline — Dunn County, ND

Radicchio Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 7 May 7 – May 28
Harvest July 16 Jul 16 – Aug 20
Fall Sowing July 1 Jul 1 – Jul 15

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
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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: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

132 days in Dunn County

Growing Tips for Radicchio in Dunn County

Direct sow Radicchio outdoors after May 14 in Dunn County when soil has warmed and frost danger has passed.

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 Dunn County, ND?

Dunn County is in Zone 4a with an average last frost of May 14. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dunn County, ND?

Dunn County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 23.

🌱

Your Dunn County Garden Planner — Free

A 24-page printable planner built for Dunn County (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 Dunn County, ND. 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.