When to Plant Onion in Ashland County, WI
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.
Ashland County, Wisconsin is in USDA Zone 3b. The average last spring frost is May 20 and the first fall frost is September 27, giving you a growing season of approximately 130 days.
At an elevation of 705 feet, Ashland County receives approximately 30.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Onion to ensure they mature before fall.
Ashland County Soil Profile
Soil Type
Silt Loam
Soil pH
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.
Plant Water Budget
Onion Planting Timeline — Ashland County, WI
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
| Direct Sow | May 13 | May 13 – Jun 3 |
| Fall Sowing | July 5 | Jul 5 – Jul 19 |
| Harvest | August 19 | Aug 19 – Sep 23 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing |
| August | 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 3b
Growing Season
130 days
Growing Tips for Ashland 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 Ashland County, WI?
Ashland County is in Zone 3b with an average last frost of May 20. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ashland County, WI?
Ashland County, Wisconsin is in USDA Hardiness Zone 3b. The average last spring frost is May 20 and first fall frost is September 27.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Ashland County gardeners in Zone 3b organize planting dates, track what's growing, and never miss a planting window.
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