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When to Plant Radish in El Dorado County, CA

El Dorado County, California Zone 9b May

May to-do list for El Dorado County, California

A quick May briefing for El Dorado County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 11
Avg. first frost November 22
Soil temp (4") 62°F
Watering Critical
Pest pressure Moderate
Daylight 14.1 hrs
  1. Harvest radish as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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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.

El Dorado County, California is in USDA Zone 9b. The average last spring frost is April 11 and the first fall frost is November 22, giving you a growing season of approximately 225 days.

At an elevation of 2,714 feet, El Dorado County receives approximately 41 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Radish to ensure they mature before fall.

El Dorado County, CA (Zone 9b) Long season
225 days
Last Spring Frost April 11
225 growing days
First Fall Frost November 22
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El Dorado County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (176 days to spare)
Transplant: Mar 29 🍅 Harvest: Apr 26 – May 17
Recommended (50%) ✓ Fits season (176 days to spare)
Transplant: Apr 11 🍅 Harvest: May 9 – May 30
Safe Start (90%) ✓ Fits season (176 days to spare)
Transplant: May 7 🍅 Harvest: Jun 4 – Jun 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 El Dorado County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Radish.

How to Plant Radish

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Radish

12
successive plantings in your 225-day season

Sow every 2.4 weeks. Last sowing by Oct 18 to harvest before frost.

For a dedicated fall crop, sow by Sep 27.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 7.5" 0" ❄️ Dormant
Feb 9.2" 0" ❄️ Dormant
Mar 7" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 1.1" 1.1" 🚿 Regular watering
Jun 2.2" 0.2" 2" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.5" 1.7" 🚿 Regular watering
Oct 2.2" 1.6" 0.6" 💧 Light watering
Nov 2.2" 3.8" 0" ✅ Rainfall sufficient
Dec 6.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in El Dorado 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 ~349 GDD — county provides 2,756 GDD Excellent fit

Radish Planting Timeline — El Dorado County, CA

Radish Planting Calendar

Activity When Date Range
Direct Sow March 21 Mar 21 – Apr 11
Harvest April 18 Apr 18 – May 9
Fall Sowing September 27 Sep 27 – Oct 11

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

225 days in El Dorado County

Growing Tips for Radish in El Dorado County

Direct sow Radish outdoors after April 11 in El Dorado County when soil has warmed and frost danger has passed.

Your generous 225.0-day season in El Dorado 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 El Dorado County, CA?

El Dorado County is in Zone 9b with an average last frost of April 11. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is El Dorado County, CA?

El Dorado County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 11 and first fall frost is November 22.

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Your El Dorado County Garden Planner — Free

A 24-page printable planner built for El Dorado County (Zone 9b). 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 El Dorado County, CA. 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.