Zucchini goes outside about two weeks after your last spring frost, once the soil is about 70 °F. It bears quickly, so a second sowing a few weeks later extends the harvest. Find your zone below, or enter your ZIP code for dates based on the weather station closest to you.
Zucchini dates for your ZIP code
Planting times based on university extension guidance (UNH, Cornell, Purdue, Minnesota, Nebraska and UMass Extension). Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Zucchini planting dates by zone
| USDA zone | When to plant |
|---|---|
| Zone 3 | June 6 |
| Zone 4 | May 30 |
| Zone 5 | May 22 |
| Zone 6 | May 15 |
| Zone 7 | May 1 |
| Zone 8 | April 14 |
| Zone 9 | March 17 |
Not sure of your zone? Look it up by ZIP code.
Why zucchini waits for warm soil
Zucchini and other summer squash are tender, warm-season plants. Frost kills them, and their seeds need warm soil, about 70 °F two inches deep, to sprout well. That is usually about two weeks after the last spring frost.
How to plant zucchini
- Sow seeds about ½ inch deep directly in the garden, or set out transplants started indoors three to four weeks earlier.
- Space plants out: in hills, 3–4 seeds per hill with 5–6 feet between hills; in rows, thin to 8–12 inches apart. Bush types need 2–3 feet between rows.
- Use row covers on cold nights early on, and remove them once flowers open.
- Water deeply and keep the soil evenly moist.
- Sow a second batch about three weeks later for a longer harvest.
Harvesting zucchini
Pick zucchini small, before the fruit gets oversized, with large seeds and hard skin. Small fruit is the most tender. Check the plants every day or two in summer, because zucchini grows fast. The flowers are edible too: pick them the day they open. Taking male flowers doesn’t reduce your harvest.
Frequently asked questions
Can I plant zucchini before the last frost?
No. Frost kills zucchini, and seeds don’t sprout well until the soil is about 70 °F. Plant about two weeks after your last frost.
How many zucchini plants do I need?
Fewer than you think. One or two plants feed most households, because each plant produces for weeks.
Why are my zucchini flowers falling off?
The first flowers are usually male and drop naturally. Fruit comes from the female flowers, which have a small squash at their base.
Sources. Planting dates use the median frost dates of each USDA zone, calculated from NOAA climate data for every ZIP code in the zone.