When to plant onions in zone 7a
In zone 7a, where the last spring frost typically comes around April 16, start onions indoors December 25 to February 5 and plant out March 19 to April 2.
The zone 7a schedule for onions
- Start seeds indoors
- December 25 to February 5
- Plant out
- March 19 to April 2
- Sow outdoors
- March 5 to 19
From the median frost dates of the NOAA stations assigned to the 3,981 ZIP codes in zone 7a, and the timing recommended by Cooperative Extension guides for onions.
Dates before the last frost assume the soil has thawed and is dry enough to work: a squeezed handful crumbles instead of sticking. After a late or wet spring, wait for that even if the date has passed.
Frost risk in zone 7a
Zones are based on winter cold, not on frost dates, so the last spring frost varies a lot within a zone. Across zone 7a, the typical last frost ranges from about April 5 in the earliest tenth of ZIP codes to April 29 in the latest tenth, and the first fall frost from October 15 to November 2. For a typical place in the zone:
- April 1Risky: a later frost happens in 9 years out of 10
- April 16Typical: frost after this date in half of years
- May 3Safe: a later frost only 1 year in 10
Your dates for onions
Set your ZIP code at the top of the page and we will work out when to plant onions where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.
Onions in zone 7a cities
| City | Typical last frost | Start indoors | Plant out |
|---|---|---|---|
| Louisville/Jefferson County, KY | Mar 31 | Dec 9 to Jan 20 | Mar 3 to 17 |
| Wichita, KS | Apr 11 | Dec 20 to Jan 31 | Mar 14 to 28 |
| Lexington-Fayette urban county, KY | Apr 13 | Dec 22 to Feb 2 | Mar 16 to 30 |
| St. Louis, MO | Apr 8 | Dec 17 to Jan 28 | Mar 11 to 25 |
| Amarillo, TX | Apr 13 | Dec 22 to Feb 2 | Mar 16 to 30 |
| Providence, RI | Apr 11 | Dec 20 to Jan 31 | Mar 14 to 28 |
| Paterson, NJ | Apr 3 | Dec 12 to Jan 23 | Mar 6 to 20 |
| Bridgeport, CT | Apr 5 | Dec 14 to Jan 25 | Mar 8 to 22 |
| Meridian, ID | Apr 24 | Jan 2 to Feb 13 | Mar 27 to Apr 10 |
| Stamford, CT | Apr 12 | Dec 21 to Feb 1 | Mar 15 to 29 |
| New Haven, CT | Apr 5 | Dec 14 to Jan 25 | Mar 8 to 22 |
| Allentown, PA | Apr 20 | Dec 29 to Feb 9 | Mar 23 to Apr 6 |
How to grow onionsAll zonesOnions in zone 6bOnions in zone 7bAbout zone 7a
Sources
- How to Grow Onions in Your Garden · Utah State University Extension
- Growing Onions in a Home Garden · University of Maryland Extension
- How to Start Onions and Leeks from Seeds · University of Maryland Extension (Maryland Grows)
- Growing Onions - Sets, Plants or Seeds? · Nebraska Extension in Lancaster County
- How to Grow Onions · University of Vermont Extension
- Onions (food fact sheet) · Montana State University Extension
- Planting the Garden · University of Vermont Extension
- Rhode Island Planting Calendar for Fruits and Vegetables · University of Rhode Island Cooperative Extension
- Soil temperature conditions for vegetable seed germination · Oregon State University Extension Service
- Onion, Leek, Shallot, & Garlic (HGIC) · Clemson Cooperative Extension Home & Garden Information Center
- Allium cepa (Plant Toolbox) · NC State Extension
- SP 103/VH021: Florida Vegetable Gardening Guide · University of Florida IFAS Extension
- Onions and Shallots · University of Florida IFAS Gardening Solutions
- Onions (Easy Gardening) · Texas A&M AgriLife Extension
- Vegetable Planting Calendar for Maricopa County (AZ1005) · University of Arizona Cooperative Extension