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When to Plant Purslane in Pima County, AZ

Pima County, Arizona Zone 9b May

May in Pima County, Arizona — your action list

Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.

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. Collect purslane at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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

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Purslane is a succulent edible plant rich in omega-3 fatty acids, often considered a weed but increasingly valued as a nutritious green. It has a lemony, peppery flavor.

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 Purslane may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Purslane will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Purslane 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 (148 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: May 3 – Jun 7
Recommended (50%) ✓ Fits season (145 days to spare)
Start indoors: Mar 4 Transplant: Apr 1 🍅 Harvest: May 13 – Jun 17
Safe Start (90%) ✓ Fits season (138 days to spare)
Start indoors: Apr 7 Transplant: May 5 🍅 Harvest: Jun 16 – 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 Pima County

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

Soil pH

Your soil pH (6.8–8.3) is more alkaline than Purslane prefers (5.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Purslane.

Organic Matter

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

How to Plant Purslane

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Purslane

6
successive plantings in your 222-day season

Sow every 4.6 weeks. Last sowing by Sep 10 to harvest before frost.

For a dedicated fall crop, sow by Sep 14.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 895 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Purslane

Purslane 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 Purslane Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.7" 0" ❄️ Dormant
Apr 2.2" 0.5" 1.7" 🚿 Regular watering
May 2.2" 0.4" 1.8" 🚿 Regular watering
Jun 2.2" 0.5" 1.7" 🚿 Regular watering
Jul 2.2" 2.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.2" 0" ✅ Rainfall sufficient
Sep 2.2" 1.9" 0.3" 💧 Light watering
Oct 2.2" 1.4" 0.8" 💧 Light watering
Nov 2.2" 0.7" 1.5" 🚿 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.

Purslane 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.

Purslane needs ~1,362 GDD — county provides 6,049 GDD Excellent fit

Purslane Planting Timeline — Pima County, AZ

Purslane 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 13 May 13 – Jun 17
Fall Sowing September 14 Sep 14 – Sep 28

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

222 days in Pima County

Growing Tips for Purslane in Pima County

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

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

With summer highs reaching 103°F in Pima County, provide afternoon shade for Purslane and water deeply in the morning.

Your generous 222.0-day season in Pima County allows multiple plantings of Purslane. Sow every 20.0 days for continuous harvest.

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

General growing tips

Direct sow after last frost or allow to self-seed. Purslane thrives in hot, dry conditions. Harvest stem tips regularly. Contains more omega-3 fatty acids than any other leafy green.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Purslane in Pima County, AZ?

Pima County is in Zone 9b with an average last frost of April 1. Plan your Purslane 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.