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When to Plant Daikon in Sumner County, TN

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.

Sumner County, Tennessee is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 28, giving you a growing season of approximately 202 days.

At an elevation of 1,917 feet, Sumner County receives approximately 54.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92ยฐF, providing good warmth for Daikon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Daikon root diseases.

Sumner County, TN (Zone 7a) Long season
202 days
Last Spring Frost April 9
202 growing days
First Fall Frost October 28

Sumner County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Transplant: Apr 4 🍅 Harvest: May 30 – Jun 27
Recommended (50%) ✓ Fits season (118 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 2
Safe Start (90%) ✓ Fits season (121 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 16 – Jul 14

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 Sumner County

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

Soil pH

Your soil pH (5.8โ€“6.9) is within Daikon's preferred range (5.8โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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

4
successive plantings in your 202-day season

Sow every 5.7 weeks. Last sowing by Aug 19 to harvest before frost.

For a dedicated fall crop, sow by Aug 19.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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€” 5" 0" โ„๏ธ Dormant
Feb โ€” 4.3" 0" โ„๏ธ Dormant
Mar โ€” 5.2" 0" โ„๏ธ Dormant
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 4.4" 0" โœ… Rainfall sufficient
Jun 4.3" 4.5" 0" โœ… Rainfall sufficient
Jul 4.3" 6.1" 0" โœ… Rainfall sufficient
Aug 4.3" 4.8" 0" โœ… Rainfall sufficient
Sep 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Oct 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Nov โ€” 4.6" 0" โ„๏ธ Dormant
Dec โ€” 4.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Sumner 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 ~1,140 GDD — county provides 3,838 GDD Excellent fit

Daikon Planting Timeline โ€” Sumner County, TN

Daikon Planting Calendar

Activity When Date Range
Direct Sow March 26 Mar 26 โ€“ Apr 16
Harvest May 21 May 21 โ€“ Jun 18
Fall Sowing August 19 Aug 19 โ€“ Sep 2

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 5.8โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

202 days in Sumner County

Growing Tips for Daikon in Sumner County

Direct sow Daikon outdoors after April 09 in Sumner 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 Sumner County, TN?

Sumner County is in Zone 7a with an average last frost of April 9. Plan your Daikon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sumner County, TN?

Sumner County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sumner County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sumner County, TN. Local conditions may vary. Last updated: April 2026.