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When to Plant Sunflower in Gila County, AZ

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Gila County, Arizona is in USDA Zone 7b. The average last spring frost is February 13 and the first fall frost is December 5, giving you a growing season of approximately 295 days.

At an elevation of 3,643 feet, Gila County receives approximately 9.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94ยฐF, providing good warmth for Sunflower during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Sunflower will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Sunflower successfully. Mulch heavily to conserve soil moisture.

Gila County, AZ (Zone 7b) Year-round
295 days
Last Spring Frost February 13
295 growing days
First Fall Frost December 5

Gila County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.7-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (164 days to spare)
Start indoors: Dec 16 Transplant: Feb 17 🍅 Harvest: Apr 28 – Jun 16
Recommended (50%) ✓ Fits season (162 days to spare)
Start indoors: Dec 26 Transplant: Feb 27 🍅 Harvest: May 8 – Jun 26
Safe Start (90%) ✓ Fits season (143 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🍅 Harvest: Jun 16 – Aug 4

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 Gila County

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

Soil pH

Your soil pH (6.7โ€“8.4) is more alkaline than Sunflower prefers (6.0โ€“7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Sunflower.

Organic Matter

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

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

5
successive plantings in your 295-day season

Sow every 8 weeks. Last sowing by Aug 27 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.1″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,638 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sunflower

Sunflower 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 Sunflower Needs Rainfall You Supplement Action
Jan โ€” 0.6" 0" โ„๏ธ Dormant
Feb 2.2" 0.6" 1.6" ๐Ÿšฟ Regular watering
Mar 2.2" 0.5" 1.7" ๐Ÿšฟ Regular watering
Apr 2.2" 0.3" 1.9" ๐Ÿšฟ Regular watering
May 2.2" 0.2" 2" ๐Ÿšฟ Regular watering
Jun 2.2" 0.3" 1.9" ๐Ÿšฟ Regular watering
Jul 2.2" 1.5" 0.7" ๐Ÿ’ง Light watering
Aug 2.2" 1.8" 0.4" ๐Ÿ’ง Light watering
Sep 2.2" 1.5" 0.7" ๐Ÿ’ง Light watering
Oct 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Nov 2.2" 0.5" 1.7" ๐Ÿšฟ Regular watering
Dec 2.2" 0.7" 1.5" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Gila County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sunflower 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" โ€” every day above 50ยฐF 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.

Sunflower needs ~1,742 GDD — county provides 6,068 GDD Excellent fit

Sunflower Planting Timeline โ€” Gila County, AZ

Sunflower Planting Calendar

Activity When Date Range
Start Indoors December 26 Dec 26 โ€“ Jan 9
Transplant Outdoors February 27 Feb 27 โ€“ Mar 13
Direct Sow February 20 Feb 20 โ€“ Mar 13
Harvest May 8 May 8 โ€“ Jun 26

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
May Harvest
June Harvest
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December Start Indoors

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

295 days in Gila County

Growing Tips for Sunflower in Gila County

Direct sow Sunflower outdoors after February 13 in Gila County when soil has warmed and frost danger has passed.

Sandy soil in Gila County dries quickly โ€” mulch Sunflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Gila County receives only 9" of rain annually. Sunflower needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Gila County, AZ?

Gila County is in Zone 7b with an average last frost of February 13. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Gila County, AZ?

Gila County, Arizona is in USDA Hardiness Zone 7b. The average last spring frost is February 13 and first fall frost is December 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Gila County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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 Gila County, AZ. Local conditions may vary. Last updated: April 2026.