When to Plant Summer Squash and Zucchini in Virginia: Spring and Fall Dates by Zone
What Virginia’s extension calendar says about summer squash, copied region by region, plus the frost record at Roanoke Regional Airport, Charlottesville Airport, and Richmond International Airport.
Updated
Figures checked against their sources on ; next check .
Virginia is covered by Virginia Cooperative Extension’s own table, and summer squash sit under the heading “Squash, summer”, in it as a separate row for 6 zones. The earliest date in the table is April 1 in Zone 8b, and the latest is May 10 in Zone 6a, a gap of 39 days. Whether the dates mean seed or set-out plants is left unsaid for this row.
What Virginia Cooperative Extension prints for summer squash
Table 5 of the same guide puts squash, summer at 1-2 plants per person, with 3 plantings in spring and summer and none in fall.
| Zone | Spring planting | Fall planting |
|---|---|---|
| Zone 6a | May 10-June 20 | June 20-Aug 10 |
| Zone 6b | May 5-June 10 | June 10-Aug 10 |
| Zone 7a | April 20-June 20 | June 20-Aug 20 |
| Zone 7b | April 10-June 20 | June 20-Sept 1 |
| Zone 8a | April 10-July 1 | July 1-Sept 10 |
| Zone 8b | April 1-July 1 | July 1-Sept 10 |
What to know about this source
Virginia Cooperative Extension builds its planting guide on USDA hardiness zones, from 6a to 8b, and prints a separate table of dates for each pair of zones. The guide says row cover fabric and cold frames may extend the expected planting and harvest window by two to four weeks in spring and in fall.
Starting summer squash indoors
None of the figures in this section belong to Virginia. They are general: UNH, for one, puts the time from seed to transplant at 3 to 4 weeks.
Only UNH puts a number of weeks on summer squash; the Minnesota row in the table is a handling tip, not a schedule.
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 Virginia stations
A 50% frost date is a coin flip, not a promise. In half of the years the last spring freeze comes later than the date shown, and in half of them the first fall freeze comes earlier.
The source leaves it to the reader to place a city among its zones, and this table does not make that call.
| Station | Last spring 32°F | First fall 32°F | Region in the calendar |
|---|---|---|---|
| Roanoke Regional Airport, Virginia | April 3 | November 1 | Not stated by the source |
| Charlottesville Airport, Virginia | April 3 | November 1 | Not stated by the source |
| Richmond International Airport, Virginia | April 3 | November 4 | Not stated by the source |
| Norfolk International Airport, Virginia | March 17 | November 23 | Not stated by the source |
| Washington DC Dulles Airport, Virginia | April 15 | October 24 | Not stated by the source |
Worked example
Take Norfolk International Airport, Virginia. NOAA’s 1991-2020 normals put the 50% last spring 32°F night on March 17 and the 50% first fall one on November 23.
The calendar does not say which zone Norfolk International Airport belongs to, so set the date against the rows at each end. Zone 8b opens April 1, 15 days after that date; Zone 6a opens May 10, 54 days after it.
None of this predicts next spring. It only lines up two published sets of dates; swap in your own station from the frost dates tool and the same steps apply.
Before you rely on these dates
The guide says actual last and first killing frost dates vary with local conditions and from year to year, and invites gardeners to favor earlier or later dates within a range.
A late cold snap after a mild March is the usual way these windows go wrong; keep a sheet or row cover on hand.
Sources (4)
- Virginia Cooperative Extension, Virginia Tech (Jadrnicek and Hessler), Virginia's Home Garden Vegetable Planting Guide: Recommended Planting Dates and Amounts to Plant, publication 426-331 (SPES-673P), May 30, 2025 pubs.ext.vt.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