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When to Plant Daikon in Webster County, IA

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.

Webster County, Iowa is in USDA Zone 4b. The average last spring frost is April 28 and the first fall frost is October 6, giving you a growing season of approximately 161 days.

At an elevation of 1,065 feet, Webster County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Daikon to ensure they mature before fall.

Webster County, IA (Zone 4b) Moderate season
161 days
Last Spring Frost April 28
161 growing days
First Fall Frost October 6

Webster County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Transplant: Apr 22 🍅 Harvest: Jun 17 – Jul 15
Recommended (50%) ✓ Fits season (77 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 23 – Jul 21
Safe Start (90%) ✓ Fits season (72 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 Webster County

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

Soil pH

Your soil pH (6.2โ€“7.3) overlaps with Daikon's range (5.8โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Webster County is excellent for Daikon โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Daikon.

Organic Matter

Organic matter is excellent (4.4%) โ€” Daikon will thrive.

How to Plant Daikon

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 Daikon

3
successive plantings in your 161-day season

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

For a dedicated fall crop, sow by Jul 14.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 734 gal / 100 sq ft

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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 2.3" 0" โ„๏ธ Dormant
Apr 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
May 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Jun 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jul 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Aug 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Sep 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Oct 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Nov โ€” 2.2" 0" โ„๏ธ Dormant
Dec โ€” 1.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Webster County). Supplement amounts are based on average rainfall โ€” 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" 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.

Daikon needs ~600 GDD — county provides 1,610 GDD Excellent fit

Daikon Planting Timeline โ€” Webster County, IA

Daikon Planting Calendar

Activity When Date Range
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest June 16 Jun 16 โ€“ Jul 14
Fall Sowing July 14 Jul 14 โ€“ Jul 28

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 5.8โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

161 days in Webster County

Growing Tips for Daikon in Webster County

Direct sow Daikon outdoors after April 28 in Webster 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 Webster County, IA?

Webster County is in Zone 4b with an average last frost of April 28. Plan your Daikon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Webster County, IA?

Webster County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 28 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Webster County gardeners in Zone 4b 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 Webster County, IA. Local conditions may vary. Last updated: April 2026.