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When to Plant Turmeric in King 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.

King County, Washington is in USDA Zone 9a. The average last spring frost is April 7 and the first fall frost is October 30, giving you a growing season of approximately 206 days.

At an elevation of 258 feet, King County receives approximately 37.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Turmeric during the growing season.

King County, WA (Zone 9a) Long season
206 days
Last Spring Frost April 7
206 growing days
First Fall Frost October 30

King County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.4

Drainage

Well Drained

Monthly Watering Guide for Turmeric

Turmeric needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Turmeric Needs Rainfall You Supplement Action
Jan 5.9" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.7" 3.6" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 5.6" 0" ❄️ Dormant
Dec 5.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in King County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Turmeric Planting Timeline — King County, WA

Turmeric Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors April 14 Apr 14 – Apr 28
Direct Sow April 7 Apr 7 – Apr 28
Harvest December 15 Dec 15 – Feb 9

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

High — keep soil consistently moist

📅 Days to Maturity

240–300 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

206 days in King County

Growing Tips for King 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turmeric in King County, WA?

King County is in Zone 9a with an average last frost of April 7. Plan your Turmeric planting based on this frost date — see the calendar above for exact timing.

What planting zone is King County, WA?

King County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is April 7 and first fall frost is October 30.

🌱

Your King County Garden Planner — Free

A 22-page printable planner built for King County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for King County, WA. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.