Planting Date · Onions
Onions Planting Date Calculator
Calculate the optimal planting dates for onions based on your USDA zone, last frost date, and preferred start method.
Optimal Soil Temp
50°F
Days to Maturity
100 days
Frost Tolerance
hardy
Planting Depth
1/2 inch (seeds) or 1 inch (sets)
Input
Fill in the fields below, then click Calculate.
Select your USDA plant hardiness zone (3–10).
Approximate month of your last spring frost.
How you plan to start the crop.
No results yet
Fill in the fields and click Calculate to see results.
Tips & Best Practices
- Start onion seeds indoors 8–10 weeks before the last frost.
- Transplant seedlings or plant sets 4–6 weeks before the last frost.
- Choose the right day-length variety for your latitude (short, intermediate, or long day).
- Stop watering when tops begin to fall over to encourage curing.