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When to Plant Radish in Coconino County, AZ

Coconino County, Arizona Zone 7a May

Your May gardening checklist

Your Coconino County, Arizona garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 28
Avg. first frost September 27
Soil temp (4") 37°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Direct-sow radish

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

Looking ahead to 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.

Coconino County, Arizona is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 27, giving you a growing season of approximately 122 days.

At an elevation of 7,869 feet, Coconino County receives approximately 13.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Radish may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Radish will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Radish successfully. Mulch heavily to conserve soil moisture.

Coconino County, AZ (Zone 7a) Short season
122 days
Last Spring Frost May 28
122 growing days
First Fall Frost September 27

Coconino County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Transplant: Apr 17 🍅 Harvest: May 15 – Jun 5
Recommended (50%) ✓ Fits season (73 days to spare)
Transplant: May 28 🍅 Harvest: Jun 25 – Jul 16
Safe Start (90%) ✓ Fits season (85 days to spare)
Transplant: Jun 24 🍅 Harvest: Jul 22 – Aug 12

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 Coconino County

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

Soil pH

Your soil pH (7.2–8.6) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Coconino County warms quickly in spring but drains fast. Radish will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting 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 122-day season

Sow every 2.4 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Jul 19.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 223 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 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.4" 0" ❄️ Dormant
May 2.2" 0.3" 1.9" 🚿 Regular watering
Jun 2.2" 0.4" 1.8" 🚿 Regular watering
Jul 2.2" 2.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3" 0" ✅ Rainfall sufficient
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Coconino 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 ~627 GDD — county provides 2,684 GDD Excellent fit

Radish Planting Timeline — Coconino County, AZ

Radish Planting Calendar

Activity When Date Range
Direct Sow May 14 May 14 – Jun 4
Harvest June 11 Jun 11 – Jul 2
Fall Sowing July 19 Jul 19 – Aug 2

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow Harvest
July Fall Sowing Harvest
August Fall Sowing
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 7a

📆 Growing Season

122 days in Coconino County

Growing Tips for Radish in Coconino County

Direct sow Radish outdoors after May 28 in Coconino County when soil has warmed and frost danger has passed.

Sandy soil in Coconino County dries quickly — mulch Radish with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Summer highs in Coconino County reach 96°F — grow Radish as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 122.0-day season in Coconino 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 Coconino County, AZ?

Coconino County is in Zone 7a with an average last frost of May 28. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coconino County, AZ?

Coconino County, Arizona is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 27.

🌱

Your Coconino County Garden Planner — Free

A 24-page printable planner built for Coconino County (Zone 7a). 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 Coconino County, AZ. 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.