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When to Plant Daikon in Lee 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.

Lee County, Iowa is in USDA Zone 5b. The average last spring frost is April 16 and the first fall frost is October 18, giving you a growing season of approximately 185 days.

At an elevation of 1,393 feet, Lee County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Daikon to ensure they mature before fall.

Lee County, IA (Zone 5b) Moderate season
185 days
Last Spring Frost April 16
185 growing days
First Fall Frost October 18

Lee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (101 days to spare)
Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 3
Recommended (50%) ✓ Fits season (101 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 9
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: May 2 🍅 Harvest: Jun 27 – Jul 25

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 Lee County

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

Soil pH

Your soil pH (6.1โ€“7.2) overlaps with Daikon's range (5.8โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Lee 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 10 weeks before your first frost date for a fall harvest.

Succession Planting Daikon

4
successive plantings in your 185-day season

Sow every 5.7 weeks. Last sowing by Aug 09 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

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 765 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€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 2.9" 0" โ„๏ธ Dormant
Apr 4.3" 3.3" 1" ๐Ÿ’ง Light watering
May 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jun 4.3" 4.3" 0" โœ… Rainfall sufficient
Jul 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Aug 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Sep 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Oct 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Nov โ€” 3" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Lee 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 ~780 GDD — county provides 2,405 GDD Excellent fit

Daikon Planting Timeline โ€” Lee County, IA

Daikon Planting Calendar

Activity When Date Range
Direct Sow April 2 Apr 2 โ€“ Apr 23
Harvest May 28 May 28 โ€“ Jun 25
Fall Sowing August 9 Aug 9 โ€“ Aug 23

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 Harvest
June Harvest
July โ€”
August Fall Sowing
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 5b

๐Ÿ“† Growing Season

185 days in Lee County

Growing Tips for Daikon in Lee County

Direct sow Daikon outdoors after April 16 in Lee 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 Lee County, IA?

Lee County is in Zone 5b with an average last frost of April 16. Plan your Daikon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lee County, IA?

Lee County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 16 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lee County gardeners in Zone 5b 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 Lee County, IA. Local conditions may vary. Last updated: April 2026.