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When to Plant Purslane in Humboldt County, CA

Humboldt County, California Zone 9b May

Your May planting checklist for Humboldt County, California

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

Avg. last frost February 27
Avg. first frost November 28
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 14.3 hrs
  1. It's harvest week for purslane

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

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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.

Humboldt County, California is in USDA Zone 9b. The average last spring frost is February 27 and the first fall frost is November 28, giving you a growing season of approximately 274 days.

At an elevation of 148 feet, Humboldt County receives approximately 22.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Purslane during the growing season. Sandy soil warms quickly in spring — great for early planting — but Purslane will need more frequent watering and organic matter to retain nutrients.

Humboldt County, CA (Zone 9b) Year-round
274 days
Last Spring Frost February 27
274 growing days
First Fall Frost November 28
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Humboldt County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (206 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: Mar 27 – May 1
Recommended (50%) ✓ Fits season (197 days to spare)
Start indoors: Jan 30 Transplant: Feb 27 🍅 Harvest: Apr 10 – May 15
Safe Start (90%) ✓ Fits season (183 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 14 – Jun 18

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 Humboldt County

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

Soil pH

Your soil pH (6.2–6.8) is within Purslane's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help 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

8
successive plantings in your 274-day season

Sow every 4.6 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 03.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 398 gal / 100 sq ft

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 4.8" 0" ❄️ Dormant
Feb 2.2" 5" 0" ✅ Rainfall sufficient
Mar 2.2" 3.3" 0" ✅ Rainfall sufficient
Apr 2.2" 1.7" 0.5" 💧 Light watering
May 2.2" 0.5" 1.7" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.3" 1.9" 🚿 Regular watering
Oct 2.2" 0.8" 1.4" 🚿 Regular watering
Nov 2.2" 1.9" 0.3" 💧 Light watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Humboldt 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 ~762 GDD — county provides 4,193 GDD Excellent fit

Purslane Planting Timeline — Humboldt County, CA

Purslane Planting Calendar

Activity When Date Range
Start Indoors January 30 Jan 30 – Feb 13
Transplant Outdoors February 27 Feb 27 – Mar 13
Direct Sow February 6 Feb 6 – Feb 27
Harvest April 10 Apr 10 – May 15
Fall Sowing October 3 Oct 3 – Oct 17

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

274 days in Humboldt County

Growing Tips for Purslane in Humboldt County

Direct sow Purslane outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.

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

Your generous 275.0-day season in Humboldt County allows multiple plantings of Purslane. Sow every 20.0 days for continuous harvest.

Humboldt County receives only 22" 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 Humboldt County, CA?

Humboldt County is in Zone 9b with an average last frost of February 27. Plan your Purslane planting based on this frost date — see the calendar above for exact timing.

What planting zone is Humboldt County, CA?

Humboldt County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 27 and first fall frost is November 28.

🌱

Your Humboldt County Garden Planner — Free

A 24-page printable planner built for Humboldt 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 Humboldt County, CA. 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.