When to Plant Onion in Curry County, OR
Top priorities for Curry County, Oregon gardeners in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
Get ahead of June
- First harvests: onion
Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.
Curry County, Oregon is in USDA Zone 9b. The average last spring frost is March 21 and the first fall frost is November 21, giving you a growing season of approximately 245 days.
At an elevation of 295 feet, Curry County receives approximately 53.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Onion during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.
Curry County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.7
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 Curry County
How your county's soil matches Onion's growing requirements.
Soil pH
Your soil pH (5.7–6.7) overlaps with Onion's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Curry County is excellent for Onion — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.4%) — Onion will thrive.
How to Plant Onion
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Plant Water Budget
Monthly Watering Guide for Onion
Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Onion Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.2" | 0" | ❄️ Dormant |
| Feb | — | 5.6" | 0" | ❄️ Dormant |
| Mar | 4.3" | 5.5" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| May | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Jun | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Jul | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Aug | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Sep | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Oct | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Dec | — | 7.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Curry County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Onion 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.
Onion Planting Timeline — Curry County, OR
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 21 | Feb 21 – Mar 7 |
| Transplant Outdoors | March 21 | Mar 21 – Apr 4 |
| Direct Sow | February 28 | Feb 28 – Mar 21 |
| Harvest | June 20 | Jun 20 – Aug 8 |
| Fall Sowing | September 26 | Sep 26 – Oct 10 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
245 days in Curry County
Growing Tips for Onion in Curry County
Direct sow Onion outdoors after March 21 in Curry County when soil has warmed and frost danger has passed.
Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Curry County, OR?
Curry County is in Zone 9b with an average last frost of March 21. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Curry County, OR?
Curry County, Oregon is in USDA Hardiness Zone 9b. The average last spring frost is March 21 and first fall frost is November 21.
Your Curry County Garden Planner — Free
A 24-page printable planner built for Curry County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.