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When to Plant Radish in Shawnee County, KS

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

Shawnee County, Kansas is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 22, giving you a growing season of approximately 191 days.

At an elevation of 923 feet, Shawnee County receives approximately 26.3 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Radish during the growing season.

Shawnee County, KS (Zone 6a) Moderate season
191 days
Last Spring Frost April 14
191 growing days
First Fall Frost October 22

Shawnee County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Transplant: Apr 9 🍅 Harvest: May 7 – May 28
Recommended (50%) ✓ Fits season (142 days to spare)
Transplant: Apr 14 🍅 Harvest: May 12 – Jun 2
Safe Start (90%) ✓ Fits season (144 days to spare)
Transplant: Apr 30 🍅 Harvest: May 28 – Jun 18

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 Shawnee County

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

Soil pH

Your soil pH (6.2โ€“7.3) overlaps with Radish's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is excellent (4.2%) โ€” Radish will thrive.

How to Plant Radish

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Succession Planting Radish

10
successive plantings in your 191-day season

Sow every 2.4 weeks. Last sowing by Sep 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 146 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Radish

Radish needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Radish Needs Rainfall You Supplement Action
Jan โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr 2.2" 2.4" 0" โœ… Rainfall sufficient
May 2.2" 4.3" 0" โœ… Rainfall sufficient
Jun 2.2" 4.5" 0" โœ… Rainfall sufficient
Jul 2.2" 3" 0" โœ… Rainfall sufficient
Aug 2.2" 3" 0" โœ… Rainfall sufficient
Sep 2.2" 2.6" 0" โœ… Rainfall sufficient
Oct 2.2" 1.8" 0.4" ๐Ÿ’ง Light watering
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Shawnee County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Radish 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.

Radish needs ~435 GDD — county provides 2,912 GDD Excellent fit

Radish Planting Timeline โ€” Shawnee County, KS

Radish Planting Calendar

Activity When Date Range
Direct Sow March 31 Mar 31 โ€“ Apr 21
Harvest April 28 Apr 28 โ€“ May 19
Fall Sowing August 13 Aug 13 โ€“ Aug 27

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April Direct Sow Harvest
May Harvest
June โ€”
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

0.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

191 days in Shawnee County

Growing Tips for Radish in Shawnee County

Direct sow Radish outdoors after April 14 in Shawnee County when soil has warmed and frost danger has passed.

Your generous 191.0-day season in Shawnee County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.

Common pests for Radish 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 every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Shawnee County, KS?

Shawnee County is in Zone 6a with an average last frost of April 14. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Shawnee County, KS?

Shawnee County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Shawnee County gardeners in Zone 6a 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 Shawnee County, KS. Local conditions may vary. Last updated: April 2026.