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When to Plant Peas in Pima County, AZ

Pima County, Arizona Zone 9b May

May in Pima County, Arizona — your action list

Here's what deserves your attention in Pima County, Arizona this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost April 1
Avg. first frost November 9
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 13.6 hrs
  1. Pick peas

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of June
  • First harvests: peas

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Peas are a cool-season legume that fixes nitrogen in the soil. Garden peas are shelled, while snap and snow peas are eaten pod and all.

Pima County, Arizona is in USDA Zone 9b. The average last spring frost is April 1 and the first fall frost is November 9, giving you a growing season of approximately 222 days.

At an elevation of 4,327 feet, Pima County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Peas may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Peas will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Peas successfully. Mulch heavily to conserve soil moisture.

Pima County, AZ (Zone 9b) Long season
222 days
Last Spring Frost April 1
222 growing days
First Fall Frost November 9

Pima County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.8-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: May 17 – Jul 12
Recommended (50%) ✓ Fits season (110 days to spare)
Start indoors: Mar 4 Transplant: Apr 1 🍅 Harvest: May 27 – Jul 22
Safe Start (90%) ✓ Fits season (103 days to spare)
Start indoors: Apr 7 Transplant: May 5 🍅 Harvest: Jun 30 – Aug 25

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 Pima County

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

Soil pH

Your soil pH (6.8–8.3) is more alkaline than Peas prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Peas.

Organic Matter

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

How to Plant Peas

1"
Planting Depth
4"
Between Plants
18"
Between Rows

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

Succession Planting Peas

4
successive plantings in your 222-day season

Sow every 6.3 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Sep 14.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,512 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Peas

Peas needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Peas Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.7" 0" ❄️ Dormant
Apr 3" 0.5" 2.5" 🚿 Regular watering
May 3" 0.4" 2.6" 🚿 Regular watering
Jun 3" 0.5" 2.5" 🚿 Regular watering
Jul 3" 2.7" 0.3" 💧 Light watering
Aug 3" 3.2" 0" ✅ Rainfall sufficient
Sep 3" 1.9" 1.1" 💧 Light watering
Oct 3" 1.4" 1.6" 🚿 Regular watering
Nov 3" 0.7" 2.3" 🚿 Regular watering
Dec 0.9" 0" ❄️ Dormant

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

Peas 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.

Peas needs ~1,703 GDD — county provides 6,049 GDD Excellent fit

Peas Planting Timeline — Pima County, AZ

Peas Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors April 1 Apr 1 – Apr 15
Direct Sow March 11 Mar 11 – Apr 1
Harvest May 27 May 27 – Jul 22
Fall Sowing September 14 Sep 14 – Sep 28

Plant 1" deep · 4" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · 2-3 times/week

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

222 days in Pima County

Growing Tips for Peas in Pima County

Direct sow Peas outdoors after April 01 in Pima County when soil has warmed and frost danger has passed.

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

Summer highs in Pima County reach 103°F — grow Peas as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Peas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow as early as soil can be worked in spring. Inoculate seeds with rhizobium for best nitrogen fixation. Provide trellising for climbing varieties.

Recommended Peas Varieties for Pima County

Heat-tolerant peas — plant very early or as fall crop

Wando (68d) Oregon Sugar Pod (60d)

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peas Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let pods dry brown and papery on the vine.
Storage Store airtight; viable 3 years at 35°F, under 45% humidity.

Very easy to save. Self-pollinating means varieties stay true.

Frequently Asked Questions

When should I plant Peas in Pima County, AZ?

Pima County is in Zone 9b with an average last frost of April 1. Plan your Peas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pima County, AZ?

Pima County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is April 1 and first fall frost is November 9.

🌱

Your Pima County Garden Planner — Free

A 24-page printable planner built for Pima County (Zone 9b). 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 Pima 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.