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When to Plant Radish in Allen 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.

Allen County, Kansas is in USDA Zone 6a. The average last spring frost is April 8 and the first fall frost is October 25, giving you a growing season of approximately 200 days.

At an elevation of 578 feet, Allen County receives approximately 26.6 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Radish during the growing season.

Allen County, KS (Zone 6a) Long season
200 days
Last Spring Frost April 8
200 growing days
First Fall Frost October 25

Allen County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (150 days to spare)
Transplant: Apr 3 🍅 Harvest: May 1 – May 22
Recommended (50%) ✓ Fits season (151 days to spare)
Transplant: Apr 8 🍅 Harvest: May 6 – May 27
Safe Start (90%) ✓ Fits season (156 days to spare)
Transplant: Apr 19 🍅 Harvest: May 17 – Jun 7

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 Allen County

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

Soil pH

Your soil pH (6.5โ€“7.8) is more alkaline than Radish prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) 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

11
successive plantings in your 200-day season

Sow every 2.4 weeks. Last sowing by Sep 20 to harvest before frost.

For a dedicated fall crop, sow by Aug 16.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr 2.2" 2.7" 0" โœ… Rainfall sufficient
May 2.2" 4.1" 0" โœ… Rainfall sufficient
Jun 2.2" 4.9" 0" โœ… Rainfall sufficient
Jul 2.2" 3.6" 0" โœ… Rainfall sufficient
Aug 2.2" 2.7" 0" โœ… Rainfall sufficient
Sep 2.2" 2.2" 0" โœ… Rainfall sufficient
Oct 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Allen 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 ~456 GDD — county provides 3,200 GDD Excellent fit

Radish Planting Timeline โ€” Allen County, KS

Radish Planting Calendar

Activity When Date Range
Direct Sow March 25 Mar 25 โ€“ Apr 15
Harvest April 22 Apr 22 โ€“ May 13
Fall Sowing August 16 Aug 16 โ€“ Aug 30

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 Natural rainfall sufficient

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

200 days in Allen County

Growing Tips for Radish in Allen County

Direct sow Radish outdoors after April 08 in Allen County when soil has warmed and frost danger has passed.

Your generous 200.0-day season in Allen 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 Allen County, KS?

Allen County is in Zone 6a with an average last frost of April 8. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Allen County, KS?

Allen County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 8 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Allen 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 Allen County, KS. Local conditions may vary. Last updated: April 2026.