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When to Plant Turmeric in Multnomah County, OR

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.

Multnomah County, Oregon is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.

At an elevation of 357 feet, Multnomah County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Turmeric to ensure they mature before fall.

Multnomah County, OR (Zone 8b) Moderate season
196 days
Last Spring Frost April 14
196 growing days
First Fall Frost October 27

Multnomah County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (285 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Dec 23 – Jan 6
Recommended (50%) ✓ Fits season (288 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.

Soil Compatibility in Multnomah County

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

Soil pH

Your soil pH (5.8โ€“6.3) is within Turmeric's preferred range (5.5โ€“7.5).

Soil Texture

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

Drainage

Turmeric is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is excellent (4.5%) โ€” Turmeric will thrive.

How to Plant Turmeric

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

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 2,060 gal / 100 sq ft

Monthly Watering Guide for Turmeric

Turmeric needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Turmeric Needs Rainfall You Supplement Action
Jan โ€” 5.8" 0" โ„๏ธ Dormant
Feb โ€” 4.1" 0" โ„๏ธ Dormant
Mar โ€” 3.5" 0" โ„๏ธ Dormant
Apr 6.5" 2.3" 4.2" ๐Ÿšฟ Regular watering
May 6.5" 2.3" 4.2" ๐Ÿšฟ Regular watering
Jun 6.5" 1.3" 5.2" ๐Ÿšฟ Regular watering
Jul 6.5" 0.6" 5.9" ๐Ÿšฟ Regular watering
Aug 6.5" 0.7" 5.8" ๐Ÿšฟ Regular watering
Sep 6.5" 1.6" 4.9" ๐Ÿšฟ Regular watering
Oct 6.5" 2.9" 3.6" ๐Ÿšฟ Regular watering
Nov โ€” 6" 0" โ„๏ธ Dormant
Dec โ€” 4.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Multnomah County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Turmeric 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.

Turmeric needs ~3,510 GDD — county provides 2,548 GDD May not mature

Turmeric Planting Timeline โ€” Multnomah County, OR

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

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

240โ€“300 days

๐Ÿงช Soil pH

Needs 5.5โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

196 days in Multnomah County

Growing Tips for Turmeric in Multnomah County

Direct sow Turmeric outdoors after April 14 in Multnomah County when soil has warmed and frost danger has passed.

Your 196.0-day growing season in Multnomah County is tight for Turmeric (240.0-300.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

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 Multnomah County, OR?

Multnomah County is in Zone 8b 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 Multnomah County, OR?

Multnomah County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

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