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When to Plant Radish in Inyo County, CA

Inyo County, California Zone 8b May

May in the garden — Inyo County, California

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost January 15
Avg. first frost December 10
Soil temp (4") 57°F
Watering Critical
Pest pressure Moderate
Daylight 13.9 hrs

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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.

Inyo County, California is in USDA Zone 8b. The average last spring frost is January 15 and the first fall frost is December 10, giving you a growing season of approximately 329 days.

At an elevation of 4,562 feet, Inyo County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°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.

Inyo County, CA (Zone 8b) Year-round
329 days
Last Spring Frost January 15
329 growing days
First Fall Frost December 10
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Inyo County Soil Profile

Soil Type

Loam

Soil pH

6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (283 days to spare)
Transplant: Jan 7 🍅 Harvest: Feb 4 – Feb 25
Recommended (50%) ✓ Fits season (280 days to spare)
Transplant: Jan 15 🍅 Harvest: Feb 12 – Mar 5
Safe Start (90%) ✓ Fits season (266 days to spare)
Transplant: Feb 9 🍅 Harvest: Mar 9 – Mar 30

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 Inyo County

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

Soil pH

Your soil pH (6.0–7.8) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). 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

19
successive plantings in your 329-day season

Sow every 2.4 weeks. Last sowing by Nov 05 to harvest before frost.

For a dedicated fall crop, sow by Oct 01.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.2″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 1,027 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.2" 3.3" 0" ✅ Rainfall sufficient
Feb 2.2" 3.4" 0" ✅ Rainfall sufficient
Mar 2.2" 2.5" 0" ✅ Rainfall sufficient
Apr 2.2" 1.3" 0.9" 💧 Light watering
May 2.2" 0.5" 1.7" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.2" 2" 🚿 Regular watering
Oct 2.2" 0.6" 1.6" 🚿 Regular watering
Nov 2.2" 1.7" 0.5" 💧 Light watering
Dec 2.2" 2.8" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Jan–Dec in Inyo 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 ~456 GDD — county provides 5,280 GDD Excellent fit

Radish Planting Timeline — Inyo County, CA

Radish Planting Calendar

Activity When Date Range
Direct Sow January 1 Jan 1 – Jan 22
Harvest January 29 Jan 29 – Feb 19
Fall Sowing October 1 Oct 1 – Oct 15

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

329 days in Inyo County

Growing Tips for Radish in Inyo County

Direct sow Radish outdoors after January 15 in Inyo County when soil has warmed and frost danger has passed.

Your generous 330.0-day season in Inyo 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 Inyo County, CA?

Inyo County is in Zone 8b with an average last frost of January 15. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Inyo County, CA?

Inyo County, California is in USDA Hardiness Zone 8b. The average last spring frost is January 15 and first fall frost is December 10.

🌱

Your Inyo County Garden Planner — Free

A 24-page printable planner built for Inyo County (Zone 8b). 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 Inyo 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.