When to plant zucchini

Planting dates for zucchini at your ZIP code, from local frost records and extension advice.

Frost risk you'll accept

Historical frost averages plus extension guidance, not a forecast. Check the forecast and soil temperature before planting.

Sow zucchini outdoors from your last spring frost date to about 3 weeks after it, once the soil is at least 60°F. If you'd like a head start, sow seeds indoors 1–3 weeks before the last frost and plant them out 1–3 weeks after it. Zucchini is killed by frost but grows fast, so a later sowing still gives a big harvest.

Frost tolerance
Tender: no frost
Soil temperature
60°F minimum; 70–95°F is ideal
Days to harvest
45–60 days from seed

The rule we use

Sowing zucchini outside

Zucchini germinates poorly in cold soil, and seed can rot before it sprouts. Wait until the soil is at least 60°F at planting depth. Sow two or three seeds about 1 inch deep in each spot, then thin to the strongest seedling. Give each plant a lot of room: a bush zucchini easily spreads 3 feet across.

If you start seeds indoors, keep it short. Squash grows fast and dislikes having its roots disturbed, so sow in individual pots no more than 2–3 weeks before planting out, and harden seedlings off for about a week.

Plant a second round

One or two plants are enough for most households, but they tend to slow down by midsummer as pests and powdery mildew build up. A second sowing 4–6 weeks after the first keeps young, healthy plants coming. That works where you have at least 60–70 frost-free days left after the second sowing.

Squash vine borers are a common reason plants suddenly wilt in the East and Midwest. The moths lay eggs in early summer. Some gardeners in borer areas cover young plants with row cover until flowering, or plant a later round that misses the main egg-laying period.

Harvest small and often

Pick zucchini at about 6–8 inches long, when the skin is still glossy. Check plants every day or two in summer: fruits double in size fast, and leaving big ones on the plant slows new ones. Flowers need bees to set fruit, so if young fruits shrivel early, poor pollination is the usual cause, especially in cool or rainy weather.

Seeds and supplies for zucchini

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Questions about planting zucchini

What month should I plant zucchini?

In the South it's usually March to April, in the Mid-Atlantic and Midwest it's May, and in the far North or the mountains it's late May to June. Enter your ZIP above for dates based on your own frost records.

Can I plant zucchini in July?

Often, yes. Zucchini needs about 45–60 days to start cropping. If your first fall frost is more than about 10 weeks away, a July sowing still has time to produce.

Should I start zucchini indoors or sow it outside?

Direct sowing is easiest once the soil is warm. Starting indoors only helps in short seasons; if you do, sow in individual pots 2–3 weeks before planting out so the roots aren't disturbed.

Why are my zucchini plants flowering but not making fruit?

The first flowers are usually male, and females follow a week or so later. If small fruits turn yellow and shrivel, they weren't pollinated. This often happens in cool, wet weather when bees are less active.

Sources

More crop guides