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When to Plant Daikon in Douglas County, SD

Douglas County, South Dakota Zone 5a May

Your May planting checklist for Douglas County, South Dakota

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Douglas County, South Dakota.

Avg. last frost May 1
Avg. first frost October 6
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
Looking ahead to June
  • First harvests: daikon

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Daikon is a large, mild Japanese radish that can grow over a foot long. It is excellent for pickling, stir-fries, and as a soil-breaking cover crop.

Douglas County, South Dakota is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 6, giving you a growing season of approximately 158 days.

At an elevation of 737 feet, Douglas County receives approximately 34.5 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Daikon to ensure they mature before fall.

Douglas County, SD (Zone 5a) Moderate season
158 days
Last Spring Frost May 1
158 growing days
First Fall Frost October 6

Douglas County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Transplant: Apr 24 🍅 Harvest: Jun 19 – Jul 17
Recommended (50%) ✓ Fits season (74 days to spare)
Transplant: May 1 🍅 Harvest: Jun 26 – Jul 24
Safe Start (90%) ✓ Fits season (71 days to spare)
Transplant: May 14 🍅 Harvest: Jul 9 – Aug 6

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 Douglas County

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

Soil pH

Your soil pH (6.7–7.4) is more alkaline than Daikon prefers (5.8–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Daikon.

How to Plant Daikon

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Daikon

3
successive plantings in your 158-day season

Sow every 5.7 weeks. Last sowing by Jul 28 to harvest before frost.

For a dedicated fall crop, sow by Jul 28.

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 140 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Daikon

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

Month Daikon Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.1" 0" ❄️ Dormant
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 5.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Daikon 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.

Daikon needs ~690 GDD — county provides 1,817 GDD Excellent fit

Daikon Planting Timeline — Douglas County, SD

Daikon Planting Calendar

Activity When Date Range
Direct Sow April 17 Apr 17 – May 8
Harvest June 12 Jun 12 – Jul 10
Fall Sowing July 28 Jul 28 – Aug 11

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June Harvest
July Fall Sowing Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.8–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

158 days in Douglas County

Growing Tips for Daikon in Douglas County

Direct sow Daikon outdoors after May 01 in Douglas County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow in late summer for fall harvest. Loosen soil deeply before planting. Thin seedlings to 6 inches apart. Harvest before hard freeze as exposed shoulders may crack.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Daikon in Douglas County, SD?

Douglas County is in Zone 5a with an average last frost of May 1. Plan your Daikon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Douglas County, SD?

Douglas County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 6.

🌱

Your Douglas County Garden Planner — Free

A 24-page printable planner built for Douglas County (Zone 5a). 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 Douglas County, SD. Local conditions may vary. Last updated: May 2026.

Sources & credits

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