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When to Plant Corn in Greenlee County, AZ

Greenlee County, Arizona Zone 8a May

May in the garden — Greenlee County, Arizona

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

Avg. last frost April 22
Avg. first frost October 22
Soil temp (4") 59°F
Watering Critical
Pest pressure Moderate
Daylight 13.7 hrs

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Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Greenlee County, Arizona is in USDA Zone 8a. The average last spring frost is April 22 and the first fall frost is October 22, giving you a growing season of approximately 183 days.

At an elevation of 4,156 feet, Greenlee County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Corn may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Corn will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Corn successfully. Mulch heavily to conserve soil moisture.

Greenlee County, AZ (Zone 8a) Moderate season
183 days
Last Spring Frost April 22
183 growing days
First Fall Frost October 22
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Greenlee County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.1-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 10 🍅 Harvest: Jun 12 – Aug 7
Recommended (50%) ✓ Fits season (64 days to spare)
Transplant: Apr 22 🍅 Harvest: Jun 24 – Aug 19
Safe Start (90%) ✓ Fits season (34 days to spare)
Transplant: Jun 18 🍅 Harvest: Aug 20 – Oct 15

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 Greenlee County

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

Soil pH

Your soil pH (7.1–8.3) is more alkaline than Corn prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Corn.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Corn.

How to Plant Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Corn

3
successive plantings in your 183-day season

Sow every 6.9 weeks. Last sowing by Jul 14 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.3″/week
You supply
1.9″/week
Watering frequency 2-3 times/week
Season total 3,165 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Corn

Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Corn Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 6.5" 0.5" 6" 🚿 Regular watering
May 6.5" 0.4" 6.1" 🚿 Regular watering
Jun 6.5" 0.5" 6" 🚿 Regular watering
Jul 6.5" 2.7" 3.8" 🚿 Regular watering
Aug 6.5" 2.9" 3.6" 🚿 Regular watering
Sep 6.5" 1.7" 4.8" 🚿 Regular watering
Oct 6.5" 1.3" 5.2" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greenlee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Corn 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.

Corn needs ~1,700 GDD — county provides 3,888 GDD Excellent fit

Corn Planting Timeline — Greenlee County, AZ

Corn Planting Calendar

Activity When Date Range
Direct Sow April 29 Apr 29 – May 20
Harvest July 1 Jul 1 – Aug 26

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

183 days in Greenlee County

Growing Tips for Corn in Greenlee County

Direct sow Corn outdoors after April 22 in Greenlee County when soil has warmed and frost danger has passed.

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

Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

Greenlee County receives only 14" of rain annually. Corn needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Recommended Corn Varieties for Greenlee County

Heat-tolerant varieties that silk well in high temps

Silver Queen (92d) Incredible (85d)

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Greenlee County, AZ?

Greenlee County is in Zone 8a with an average last frost of April 22. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greenlee County, AZ?

Greenlee County, Arizona is in USDA Hardiness Zone 8a. The average last spring frost is April 22 and first fall frost is October 22.

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Your Greenlee County Garden Planner — Free

A 24-page printable planner built for Greenlee County (Zone 8a). 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 Greenlee 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.