When to Plant Summer Squash and Zucchini in Kentucky: Earliest and Latest Dates by Region
University of Kentucky Cooperative Extension’s own summer squash dates for Kentucky, row by row and never averaged, beside NOAA frost dates for Louisville International Airport, Lexington Bluegrass Airport, and Bowling Green Warren County Airport.
Updated
Figures checked against their sources on ; next check .
University of Kentucky Cooperative Extension gives summer squash their own row, with dates for 3 regions. How far apart are the rows? 25 days, from April 20 in Western Kentucky to May 15 in Eastern Kentucky.
The summer squash windows by region
Kentucky’s own transplant table, Table 20.6, lists squash at 3-4 weeks from seeding to transplanting and an average seedling date of April 1.
| Region | Earliest safe planting date | Latest safe planting date |
|---|---|---|
| Western Kentucky | Apr 20 | Aug 15 |
| Central Kentucky | May 10 | Aug 1 |
| Eastern Kentucky | May 15 | July 15 |
Reading the University of Kentucky Cooperative Extension table
The University of Kentucky’s home vegetable gardening chapter gives each crop an earliest and a latest safe planting date for Western, Central and Eastern Kentucky. A separate gardener’s calendar in the chapter lists when to start seeds indoors, move transplants and start seeds outdoors, again for the three regions.
Starting summer squash indoors
If you raise your own transplants, count backward from the set-out date. UNH’s fact sheet allows 3 to 4 weeks for that stage, and the table lists what the others say.
Expect less guidance here than for tomatoes: summer squash get a single timed source and a note on pots.
In the garden itself, UNH sows summer squash once the soil reaches 70 °F, which a soil thermometer answers better than any calendar.
| Source | What it says |
|---|---|
| University of New Hampshire | 3 to 4 weeks from seed to transplant; 2 weeks after the last frost is safe to set out |
| University of Minnesota | Cucumbers and squash transplant poorly, so raise them in fiber or paper pots that break down in the soil |
Typical frost dates at Kentucky stations
These are station dates from weather records, not county averages. Pick the station closest to your garden and elevation, and open its link for the full set of probabilities.
The source leaves it to the reader to place a city among its regions, and this table does not make that call.
| Station | Last spring 32°F | First fall 32°F | Region in the calendar |
|---|---|---|---|
| Louisville International Airport, Kentucky | March 31 | November 7 | Not stated by the source |
| Lexington Bluegrass Airport, Kentucky | April 13 | October 28 | Not stated by the source |
| Bowling Green Warren County Airport, Kentucky | April 5 | October 31 | Not stated by the source |
| London Corbin Airport, Kentucky | April 15 | October 25 | Not stated by the source |
Worked example
NOAA’s normals for London Corbin Airport, Kentucky give April 15 as the even-odds date of the last spring 32°F night, and October 25 as the even-odds first fall one.
The calendar does not say which region London Corbin Airport belongs to, so set the date against the rows at each end. Western Kentucky opens April 20, 5 days after that date; Eastern Kentucky opens May 15, 30 days after it.
On the fall side, Eastern Kentucky’s last planting date of July 15 leaves 102 days before the October 25 median first freeze.
Do the same subtraction for your own town: choose its nearest station in the frost dates tool, take the 50% dates, and compare them with the row for your part of Kentucky.
Before you rely on these dates
The chapter says its planting dates are approximate and should be adjusted to local weather.
Soil that is cold or soaked can hold a crop back even inside the printed window, so check the ground as well as the calendar.
Sources (4)
- University of Kentucky Cooperative Extension Service (editor Richard Durham), Home Vegetable Gardening in Kentucky, ID-128, revised January 2024 publications.mgcafe.uky.edu
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020, annual and seasonal normals (frost/freeze probabilities by station) ncei.noaa.gov
- University of New Hampshire Cooperative Extension, Growing Vegetables: When to Plant Your Vegetable Garden (fact sheet) extension.unh.edu
- University of Minnesota Extension, Starting seeds indoors (page reviewed 2026) extension.umn.edu