When to Plant Onion in Klickitat County, WA
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.
Klickitat County, Washington is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 19, giving you a growing season of approximately 188 days.
At an elevation of 466 feet, Klickitat County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 77°F, so choose short-season varieties of Onion to ensure they mature before fall.
Klickitat County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.8
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.
Plant Water Budget
Onion Planting Timeline — Klickitat County, WA
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | April 14 | Apr 14 – Apr 28 |
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Fall Sowing | August 10 | Aug 10 – Aug 24 |
| Harvest | July 14 | Jul 14 – Sep 1 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
6 – 7
USDA Zone
Zone 6b
Growing Season
188 days
Growing Tips for Klickitat County
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
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Klickitat County, WA?
Klickitat County is in Zone 6b with an average last frost of April 14. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Klickitat County, WA?
Klickitat County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 19.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Klickitat County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
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