When to Plant Onion in Portage County, OH
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.
Portage County, Ohio is in USDA Zone 5b. The average last spring frost is May 4 and the first fall frost is October 13, giving you a growing season of approximately 162 days.
At an elevation of 1,164 feet, Portage County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Onion during the growing season.
Portage County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.8
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Onion Planting Timeline — Portage County, OH
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 30 | Mar 30 – Apr 13 |
| Transplant Outdoors | May 4 | May 4 – May 18 |
| Direct Sow | April 20 | Apr 20 – May 11 |
| Fall Sowing | August 4 | Aug 4 – Aug 18 |
| Harvest | August 3 | Aug 3 – Sep 21 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| 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 5b
Growing Season
162 days
Growing Tips for Portage 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 Portage County, OH?
Portage County is in Zone 5b with an average last frost of May 4. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Portage County, OH?
Portage County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is May 4 and first fall frost is October 13.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Portage County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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