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When to Plant Chard in Pinal County, AZ

Pinal County, Arizona Zone 9a May

May to-do list for Pinal County, Arizona

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 23
Avg. first frost November 27
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs
  1. Basket week: chard

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

To set up a strong June, finish these tasks
  • First harvests: chard

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Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

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 98°F, so Chard may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Chard will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Chard 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
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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 (180 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Apr 7 – May 26
Recommended (50%) ✓ Fits season (172 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🍅 Harvest: Apr 20 – Jun 8
Safe Start (90%) ✓ Fits season (160 days to spare)
Start indoors: Feb 24 Transplant: Mar 24 🍅 Harvest: May 19 – Jul 7

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 Chard's growing requirements.

Soil pH

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

Soil Texture

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

Drainage

Drainage is adequate for Chard.

Organic Matter

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

How to Plant Chard

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 Chard

6
successive plantings in your 277-day season

Sow every 5.7 weeks. Last sowing by Sep 28 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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Chard

Chard 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 Chard Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 3.5" 1" 2.5" 🚿 Regular watering
Mar 3.5" 0.8" 2.7" 🚿 Regular watering
Apr 3.5" 0.5" 3" 🚿 Regular watering
May 3.5" 0.3" 3.2" 🚿 Regular watering
Jun 3.5" 0.5" 3" 🚿 Regular watering
Jul 3.5" 3" 0.5" 💧 Light watering
Aug 3.5" 3.5" 0" ✅ Rainfall sufficient
Sep 3.5" 1.9" 1.6" 💧 Light watering
Oct 3.5" 1.5" 2" 🚿 Regular watering
Nov 3.5" 0.8" 2.7" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

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

Chard 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.

Chard needs ~1,292 GDD — county provides 6,533 GDD Excellent fit

Chard Planting Timeline — Pinal County, AZ

Chard Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 – Feb 9
Transplant Outdoors February 23 Feb 23 – Mar 9
Direct Sow February 2 Feb 2 – Feb 23
Harvest April 20 Apr 20 – Jun 8
Fall Sowing October 2 Oct 2 – Oct 16

Plant 1" deep · 15" apart · 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
August
September
October Fall Sowing
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · 2-3 times/week

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Pinal County

Growing Tips for Chard in Pinal County

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

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

Summer highs in Pinal County reach 98°F — grow Chard as a spring or fall crop. Use shade cloth if planting in summer.

General growing tips

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chard in Pinal County, AZ?

Pinal County is in Zone 9a with an average last frost of February 23. Plan your Chard planting based on this frost date — 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.

🌱

Your Pinal County Garden Planner — Free

A 24-page printable planner built for Pinal County (Zone 9a). 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 Pinal 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.