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When to Plant Turmeric in Cowlitz County, WA

Turmeric is a tropical plant producing bright orange rhizomes with a warm, earthy flavor and potent anti-inflammatory properties. It is closely related to ginger.

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 Turmeric 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 (286 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Dec 24 – Jan 7
Recommended (50%) ✓ Fits season (289 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Dec 30 – Jan 13
Safe Start (90%) ✓ Fits season (293 days to spare)
Start indoors: Mar 19 Transplant: May 21 🍅 Harvest: Jan 21 – Feb 4

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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 858 gal / 100 sq ft
Turmeric needs ~4,118 GDD — county provides 3,004 GDD May not mature

Turmeric Planting Timeline โ€” Cowlitz County, WA

Turmeric Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 โ€“ Mar 11
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest December 30 Dec 30 โ€“ Jan 13

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

240โ€“300 days

Soil pH

5.5 โ€“ 7.5

USDA Zone

Zone 8a

Growing Season

197 days

Growing Tips for Cowlitz County

Plant rhizome pieces 2 inches deep in rich, moist soil after last frost. Maintain warmth and humidity. Harvest after foliage dies back in fall. In cold climates, grow in large containers.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Turmeric in Cowlitz County, WA?

Cowlitz County is in Zone 8a with an average last frost of April 15. Plan your Turmeric 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.

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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.