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When to Plant Turmeric in Jefferson 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.

Jefferson County, Washington is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 29, giving you a growing season of approximately 198 days.

At an elevation of 205 feet, Jefferson County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Turmeric during the growing season.

Jefferson County, WA (Zone 8a) Moderate season
198 days
Last Spring Frost April 14
198 growing days
First Fall Frost October 29

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (292 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Dec 21 – Jan 4
Recommended (50%) ✓ Fits season (290 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Dec 29 – Jan 12
Safe Start (90%) ✓ Fits season (286 days to spare)
Start indoors: Mar 21 Transplant: May 23 🍅 Harvest: Jan 23 – Feb 6

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
0.9″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,915 gal / 100 sq ft
Turmeric needs ~4,320 GDD — county provides 3,168 GDD May not mature

Turmeric Planting Timeline โ€” Jefferson County, WA

Turmeric Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 โ€“ Mar 10
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest December 29 Dec 29 โ€“ Jan 12

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

198 days

Growing Tips for Jefferson 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 Jefferson County, WA?

Jefferson County is in Zone 8a with an average last frost of April 14. Plan your Turmeric planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, WA?

Jefferson County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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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 Jefferson County, WA. Local conditions may vary. Last updated: April 2026.