When to Plant Turmeric in Benton 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.
Benton County, Oregon is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.
At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Turmeric during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Turmeric root diseases.
Benton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Benton County
How your county's soil matches Turmeric's growing requirements.
Soil pH
Your soil pH (5.6–6.2) is within Turmeric's preferred range (5.5–7.5).
Soil Texture
The silt loam soil in Benton County is excellent for Turmeric — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Turmeric will thrive.
How to Plant Turmeric
Plant Water Budget
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 | — | 8.1" | 0" | ❄️ Dormant |
| Feb | — | 6.1" | 0" | ❄️ Dormant |
| Mar | — | 5.8" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| May | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Jun | 6.5" | 1.9" | 4.6" | 🚿 Regular watering |
| Jul | 6.5" | 0.9" | 5.6" | 🚿 Regular watering |
| Aug | 6.5" | 0.8" | 5.7" | 🚿 Regular watering |
| Sep | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| Oct | 6.5" | 3.8" | 2.7" | 💧 Light watering |
| Nov | — | 8.3" | 0" | ❄️ Dormant |
| Dec | — | 8.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Benton County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 Planting Timeline — Benton County, OR
Turmeric Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | December 29 | Dec 29 – Jan 12 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Harvest |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Harvest |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
240–300 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 8a
📆 Growing Season
199 days in Benton County
Growing Tips for Turmeric in Benton County
Direct sow Turmeric outdoors after April 14 in Benton County when soil has warmed and frost danger has passed.
Your 199.0-day growing season in Benton 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 →
Turmeric in Other Locations
Frequently Asked Questions
When should I plant Turmeric in Benton County, OR?
Benton County is in Zone 8a with an average last frost of April 14. Plan your Turmeric planting based on this frost date — see the calendar above for exact timing.
What planting zone is Benton County, OR?
Benton County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 30.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Benton 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.