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When to Plant Radish in Ouray County, CO

Ouray County, Colorado Zone 5b May

Your May gardening checklist

Here's what deserves your attention in Ouray County, Colorado this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost June 18
Avg. first frost September 10
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.1 hrs
Looking ahead to June
  • Direct-sowing: 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.

Ouray County, Colorado is in USDA Zone 5b. The average last spring frost is June 18 and the first fall frost is September 10, giving you a growing season of approximately 84 days.

At an elevation of 7,449 feet, Ouray County receives approximately 12.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86°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.

Ouray County, CO (Zone 5b) Very short season
84 days
Last Spring Frost June 18
84 growing days
First Fall Frost September 10
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Ouray County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Transplant: May 13 🍅 Harvest: Jun 10 – Jul 1
Recommended (50%) ✓ Fits season (35 days to spare)
Transplant: Jun 18 🍅 Harvest: Jul 16 – Aug 6
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: Jun 29 🍅 Harvest: Jul 27 – Aug 17

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 Ouray County

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

Soil pH

Your soil pH (6.4–8.3) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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

4
successive plantings in your 84-day season

Sow every 2.4 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Jul 02.

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 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 0.8" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 1.3" 0" ❄️ Dormant
Jun 2.2" 1" 1.2" 🚿 Regular watering
Jul 2.2" 1.2" 1" 💧 Light watering
Aug 2.2" 1.4" 0.8" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 1" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Ouray 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 ~413 GDD — county provides 1,218 GDD Excellent fit

Radish Planting Timeline — Ouray County, CO

Radish Planting Calendar

Activity When Date Range
Direct Sow June 4 Jun 4 – Jun 25
Harvest July 2 Jul 2 – Jul 23
Fall Sowing July 2 Jul 2 – Jul 16

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5b

📆 Growing Season

84 days in Ouray County

Growing Tips for Radish in Ouray County

Direct sow Radish outdoors after June 18 in Ouray County when soil has warmed and frost danger has passed.

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 Ouray County, CO?

Ouray County is in Zone 5b with an average last frost of June 18. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ouray County, CO?

Ouray County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 18 and first fall frost is September 10.

🌱

Your Ouray County Garden Planner — Free

A 24-page printable planner built for Ouray County (Zone 5b). 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 Ouray County, CO. 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.