When to Plant Onions in Kentucky
In Kentucky, the time to plant onions outside runs from Mar 3 – Mar 17 in Shively to Apr 3 – Apr 17 in Shelbyville. In Louisville/Jefferson County metro government, it's Mar 9 – Mar 23. The average last spring frost differs by about 4 weeks across the state (Mar 31 in Shively, May 1 in Shelbyville), so use the dates for the town nearest you.
Onions are cold-hardy. Plant sets or transplants early so they grow leaves before long summer days trigger bulbing.
- Start indoors: 10–12 weeks before the last frost.
- Plant outside: 2–4 weeks before the last frost.
Onions planting dates in Kentucky by city
| City | Zone | Start indoors | Plant outside |
|---|---|---|---|
| Alexandria | 6b | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Ashland | 7a | Jan 28 – Feb 11 | Mar 25 – Apr 8 |
| Bardstown | 7a | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Berea | 7a | Jan 11 – Jan 25 | Mar 8 – Mar 22 |
| Bowling Green | 7a | Jan 11 – Jan 25 | Mar 8 – Mar 22 |
| Campbellsville | 7a | Jan 21 – Feb 4 | Mar 18 – Apr 1 |
| Covington | 6b | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Danville | 7a | Jan 15 – Jan 29 | Mar 12 – Mar 26 |
| Elizabethtown | 7a | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Erlanger | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Florence | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Fort Thomas | 6b | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Frankfort | 6b | Jan 21 – Feb 4 | Mar 18 – Apr 1 |
| Georgetown | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Glasgow | 7a | Jan 15 – Jan 29 | Mar 12 – Mar 26 |
| Henderson | 7a | Jan 15 – Jan 29 | Mar 12 – Mar 26 |
| Hopkinsville | 7a | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Independence | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Jeffersontown | 7a | Jan 9 – Jan 23 | Mar 6 – Mar 20 |
| La Grange | 6b | Jan 18 – Feb 1 | Mar 15 – Mar 29 |
| Lawrenceburg | 6b | Jan 18 – Feb 1 | Mar 15 – Mar 29 |
| Lexington-Fayette | 7a | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Louisville/Jefferson County metro government | 7a | Jan 12 – Jan 26 | Mar 9 – Mar 23 |
| Lyndon | 7a | Jan 9 – Jan 23 | Mar 6 – Mar 20 |
| Madisonville | 7a | Jan 8 – Jan 22 | Mar 5 – Mar 19 |
| Mount Washington | 7a | Jan 12 – Jan 26 | Mar 9 – Mar 23 |
| Murray | 7b | Jan 11 – Jan 25 | Mar 8 – Mar 22 |
| Newport | 6b | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Nicholasville | 7a | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Owensboro | 7a | Jan 8 – Jan 22 | Mar 5 – Mar 19 |
| Paducah | 7a | Jan 12 – Jan 26 | Mar 9 – Mar 23 |
| Radcliff | 7a | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Richmond | 7a | Jan 21 – Feb 4 | Mar 18 – Apr 1 |
| Shelbyville | 6b | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Shepherdsville | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Shively | 7a | Jan 6 – Jan 20 | Mar 3 – Mar 17 |
| Somerset | 7a | Jan 11 – Jan 25 | Mar 8 – Mar 22 |
| St. Matthews | 7a | Jan 9 – Jan 23 | Mar 6 – Mar 20 |
| Versailles | 7a | Jan 18 – Feb 1 | Mar 15 – Mar 29 |
| Winchester | 6b | Jan 30 – Feb 13 | Mar 27 – Apr 10 |
Calculated from each town's average (50%) frost dates, from the nearest NOAA station (1991–2020). Typical dates for the 2027 planting season, based on NOAA's 1991–2020 averages. They are long-term odds, not a forecast: always check your local forecast before planting. Zones: 2023 USDA Plant Hardiness Zone Map (USDA-ARS and Oregon State University). Not the official map; see planthardiness.ars.usda.gov.
See all frost dates in Kentucky, or the general guide to when to plant onions.
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