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When to Plant Radish in Oneida County, ID

Oneida County, Idaho Zone 6a May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Oneida County, Idaho.

Avg. last frost May 23
Avg. first frost September 20
Soil temp (4") 33°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Seed radish outdoors

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

A few tasks this May that'll pay off in June
  • First harvests: radish

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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.

Oneida County, Idaho is in USDA Zone 6a. The average last spring frost is May 23 and the first fall frost is September 20, giving you a growing season of approximately 120 days.

At an elevation of 8,042 feet, Oneida County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Radish during the growing season. With low rainfall, drip irrigation is essential for growing Radish successfully. Mulch heavily to conserve soil moisture.

Oneida County, ID (Zone 6a) Short season
120 days
Last Spring Frost May 23
120 growing days
First Fall Frost September 20

Oneida County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Transplant: May 12 🍅 Harvest: Jun 9 – Jun 30
Recommended (50%) ✓ Fits season (71 days to spare)
Transplant: May 23 🍅 Harvest: Jun 20 – Jul 11
Safe Start (90%) ✓ Fits season (69 days to spare)
Transplant: Jun 15 🍅 Harvest: Jul 13 – Aug 3

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 Oneida County

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

Soil pH

Your soil pH (6.3–8.2) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Oneida County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Radish.

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

6
successive plantings in your 120-day season

Sow every 2.4 weeks. Last sowing by Aug 16 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 8 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 2.2" 2.1" 0.1" 💧 Light watering
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 2" 0.2" 💧 Light watering
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Oneida County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~392 GDD — county provides 1,650 GDD Excellent fit

Radish Planting Timeline — Oneida County, ID

Radish Planting Calendar

Activity When Date Range
Direct Sow May 9 May 9 – May 30
Harvest June 6 Jun 6 – Jun 27
Fall Sowing July 12 Jul 12 – Jul 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

120 days in Oneida County

Growing Tips for Radish in Oneida County

Direct sow Radish outdoors after May 23 in Oneida County when soil has warmed and frost danger has passed.

Your generous 120.0-day season in Oneida 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 Oneida County, ID?

Oneida County is in Zone 6a with an average last frost of May 23. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oneida County, ID?

Oneida County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 23 and first fall frost is September 20.

🌱

Your Oneida County Garden Planner — Free

A 24-page printable planner built for Oneida County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Oneida County, ID. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.