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When to Plant Purslane in Cowlitz County, WA

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.

Cowlitz County, Washington is in USDA Zone 8a. The average last spring frost is April 15 and the first fall frost is October 29, giving you a growing season of approximately 197 days.

At an elevation of 268 feet, Cowlitz County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Purslane during the growing season.

Cowlitz County, WA (Zone 8a) Moderate season
197 days
Last Spring Frost April 15
197 growing days
First Fall Frost October 29

Cowlitz County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 21 – Jun 25
Recommended (50%) ✓ Fits season (120 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1
Safe Start (90%) ✓ Fits season (124 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jun 18 – Jul 23

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 Cowlitz County

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

Soil pH

Your soil pH (5.7โ€“6.5) is within Purslane's preferred range (5.5โ€“7.5).

Soil Texture

The silt loam soil in Cowlitz County is excellent for Purslane โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” Purslane will thrive.

How to Plant Purslane

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Purslane

5
successive plantings in your 197-day season

Sow every 4.6 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 20.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 7.2" 0" โ„๏ธ Dormant
Feb โ€” 4.6" 0" โ„๏ธ Dormant
Mar โ€” 5.1" 0" โ„๏ธ Dormant
Apr 2.2" 3.6" 0" โœ… Rainfall sufficient
May 2.2" 2.9" 0" โœ… Rainfall sufficient
Jun 2.2" 2" 0.2" ๐Ÿ’ง Light watering
Jul 2.2" 0.8" 1.4" ๐Ÿšฟ Regular watering
Aug 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Sep 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Oct 2.2" 3.4" 0" โœ… Rainfall sufficient
Nov โ€” 7.6" 0" โ„๏ธ Dormant
Dec โ€” 7.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Cowlitz County). Supplement amounts are based on average rainfall โ€” 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" 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.

Purslane needs ~762 GDD — county provides 3,004 GDD Excellent fit

Purslane Planting Timeline โ€” Cowlitz County, WA

Purslane Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 โ€“ Mar 25
Transplant Outdoors April 15 Apr 15 โ€“ Apr 29
Direct Sow April 1 Apr 1 โ€“ Apr 22
Harvest May 27 May 27 โ€“ Jul 1
Fall Sowing August 20 Aug 20 โ€“ Sep 3

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 5.5โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

197 days in Cowlitz County

Growing Tips for Purslane in Cowlitz County

Direct sow Purslane outdoors after April 15 in Cowlitz County when soil has warmed and frost danger has passed.

Your generous 197.0-day season in Cowlitz County allows multiple plantings of Purslane. Sow every 20.0 days for continuous harvest.

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 Cowlitz County, WA?

Cowlitz County is in Zone 8a with an average last frost of April 15. Plan your Purslane planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cowlitz County, WA?

Cowlitz County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 15 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Cowlitz County gardeners in Zone 8a 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 Cowlitz County, WA. Local conditions may vary. Last updated: April 2026.