Blog

When to Plant Collard Greens in Pinal County, AZ

Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

Pinal County, Arizona is in USDA Zone 9a. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.

At an elevation of 3,959 feet, Pinal County receives approximately 15.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98ยฐF, so Collard Greens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Collard Greens will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Collard Greens successfully. Mulch heavily to conserve soil moisture.

Pinal County, AZ (Zone 9a) Year-round
277 days
Last Spring Frost February 23
277 growing days
First Fall Frost November 27

Pinal County Soil Profile

Soil Type

Sandy Loam

Soil pH

7-8.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (166 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Apr 7 – Jun 9
Recommended (50%) ✓ Fits season (158 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🍅 Harvest: Apr 20 – Jun 22
Safe Start (90%) ✓ Fits season (146 days to spare)
Start indoors: Feb 24 Transplant: Mar 24 🍅 Harvest: May 19 – Jul 21

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 Pinal County

How your county's soil matches Collard Greens's growing requirements.

Soil pH

Your soil pH (7.0โ€“8.6) is more alkaline than Collard Greens prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Collard Greens.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Collard Greens.

How to Plant Collard Greens

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Collard Greens

6
successive plantings in your 277-day season

Sow every 6.3 weeks. Last sowing by Sep 13 to harvest before frost.

For a dedicated fall crop, sow by Oct 02.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,379 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Collard Greens

Collard Greens needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Collard Greens Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb 3.5" 1" 2.5" ๐Ÿšฟ Regular watering
Mar 3.5" 0.8" 2.7" ๐Ÿšฟ Regular watering
Apr 3.5" 0.5" 3" ๐Ÿšฟ Regular watering
May 3.5" 0.3" 3.2" ๐Ÿšฟ Regular watering
Jun 3.5" 0.5" 3" ๐Ÿšฟ Regular watering
Jul 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Aug 3.5" 3.5" 0" โœ… Rainfall sufficient
Sep 3.5" 1.9" 1.6" ๐Ÿ’ง Light watering
Oct 3.5" 1.5" 2" ๐Ÿšฟ Regular watering
Nov 3.5" 0.8" 2.7" ๐Ÿšฟ Regular watering
Dec โ€” 1" 0" โ„๏ธ Dormant

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

Collard Greens 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.

Collard Greens needs ~1,528 GDD — county provides 6,533 GDD Excellent fit

Collard Greens Planting Timeline โ€” Pinal County, AZ

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 โ€“ Feb 9
Transplant Outdoors February 23 Feb 23 โ€“ Mar 9
Direct Sow February 2 Feb 2 โ€“ Feb 23
Harvest April 20 Apr 20 โ€“ Jun 22
Fall Sowing October 2 Oct 2 โ€“ Oct 16

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

55โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

277 days in Pinal County

Growing Tips for Collard Greens in Pinal County

Direct sow Collard Greens outdoors after February 23 in Pinal County when soil has warmed and frost danger has passed.

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

With summer highs reaching 98ยฐF in Pinal County, provide afternoon shade for Collard Greens and water deeply in the morning.

Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Pinal County, AZ?

Pinal County is in Zone 9a with an average last frost of February 23. Plan your Collard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pinal County, AZ?

Pinal County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is February 23 and first fall frost is November 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pinal County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Pinal County, AZ. Local conditions may vary. Last updated: April 2026.