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When to Plant Radicchio in Buffalo County, SD

Buffalo County, South Dakota Zone 4b May

What to do in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 9
Avg. first frost October 5
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Move radicchio into the garden

    Frost risk is low now in Buffalo County, South Dakota. If you've been covering beds overnight, you can stop.

  2. Plant radicchio from seed, right in the garden

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

To set up a strong June, finish these tasks
  • 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.

Buffalo County, South Dakota is in USDA Zone 4b. The average last spring frost is May 9 and the first fall frost is October 5, giving you a growing season of approximately 149 days.

At an elevation of 840 feet, Buffalo County receives approximately 23.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Radicchio to ensure they mature before fall.

Buffalo County, SD (Zone 4b) Short season
149 days
Last Spring Frost May 9
149 growing days
First Fall Frost October 5
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Buffalo County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jul 3 – Aug 7
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Mar 28 Transplant: May 9 🍅 Harvest: Jul 11 – Aug 15
Safe Start (90%) ✓ Fits season (50 days to spare)
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Jul 22 – Aug 26

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 Buffalo County

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

Soil pH

Your soil pH (6.5–7.8) is more alkaline than Radicchio prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Radicchio.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Radicchio.

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 149-day season

Sow every 6.9 weeks. Last sowing by Jul 17 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

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 321 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 0.6" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 3" 3.2" 0" ✅ Rainfall sufficient
Jun 3" 4.3" 0" ✅ Rainfall sufficient
Jul 3" 3.4" 0" ✅ Rainfall sufficient
Aug 3" 2.6" 0.4" 💧 Light watering
Sep 3" 2.1" 0.9" 💧 Light watering
Oct 3" 1.6" 1.4" 💧 Light watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Buffalo 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 ~858 GDD — county provides 1,825 GDD Excellent fit

Radicchio Planting Timeline — Buffalo County, SD

Radicchio Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 9 May 9 – May 23
Direct Sow May 2 May 2 – May 23
Harvest July 11 Jul 11 – Aug 15
Fall Sowing July 13 Jul 13 – Jul 27

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
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: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

149 days in Buffalo County

Growing Tips for Radicchio in Buffalo County

Direct sow Radicchio outdoors after May 09 in Buffalo 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 Buffalo County, SD?

Buffalo County is in Zone 4b with an average last frost of May 9. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Buffalo County, SD?

Buffalo County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 9 and first fall frost is October 5.

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Your Buffalo County Garden Planner — Free

A 24-page printable planner built for Buffalo County (Zone 4b). 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 Buffalo County, SD. Local conditions may vary. Last updated: May 2026.

Sources & credits

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