Zucchini Plant Guide: How to Grow Zucchini, Pick It Young and Eat the Blossoms

To grow a zucchini plant, wait for the last frost to pass and for soil two inches down to hit 70 F, then plant the seed 1/2 to 1 inch down. Thin to one plant every 18 to 36 inches in most advice, or as close as 8 to 12 inches with room on each side for the vines. Zucchini needs bees: the first blooms are male, and fruit sets once female flowers open a week or two later. Pick most varieties at about 6 to 8 inches long, checking the plants daily or every few days, since the fruit swells fast. The flowers are a crop too: take mostly male blossoms the day they open and leave a few to pollinate.

Drip or a soaker hose waters zucchini while keeping its leaves dry; see which soaker hoses work best.

When to plant zucchini

Zucchini seed goes in after your last frost and only into warm ground: at least 70 F at a two-inch depth, and 70 to 85 F is the range given for sowing. The table below dates direct sowing a week or two past the average last frost. For a steady supply of young fruit, sowing again every 2 to 4 weeks may be needed, or plant two or three times a season. The last sowing goes in 8 weeks before your first fall frost date, though some advice stops planting at midsummer.

Each freeze date below is the day a station's 1991 to 2020 climate normals give even odds of a later 32 F night, so a frost after it is a coin flip.

Direct sowing = the spring freeze date plus 1 to 2 weeks, a seed company's margin after the average last frost; the soil rule still applies. Indoor start = 3 weeks before that window, the lead time given for zucchini started indoors, assuming you plant out in the sowing window. Last sowing = the fall freeze date minus 8 weeks (56 days); our squash and pumpkins guide counts back roughly 55 days to harvest instead, so its dates fall one day later.

The soil overrules the calendar. Minneapolis-St. Paul's freeze date is Apr 23, yet in most of Minnesota the soil reaches 70 F only in late May, or in early June up north; seed sown into cold soil will not sprout. A soil thermometer settles it; a hardiness zone is no substitute for a station's frost date.

Seed or transplants? Sowing in place is the more common advice, since moved seedlings suffer root damage. Transplants still get a jump on the season and give an early crop where summers are short: start them in 3-inch pots 3 weeks ahead and disturb the roots as little as possible.

What you'll need for zucchini

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  VIVOSUN 10 Gallon Grow Bags, 5-Pack

  A zucchini plant can grow in a container of at least 4 to 6 gallons, 8 to 12 inches deep; choose a compact bush type.

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  Corona FS 3214D ComfortGEL Micro Snips

  Shears and gloves for the harvest.

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How far apart to plant zucchini, and soil and water

Space zucchini plants 18 to 36 inches apart in most advice, with 3 to 6 feet between rows. The closest spacing given is 8 to 12 inches in the row, with about two or three feet left on each side for the vines to spread. Seed depth: 1/2 to 1 inch.

Soil, sun and water. Give zucchini fertile, well-drained ground at pH 5.8 to 6.8, or a narrower 6.0 to 6.5. Before planting, mix in compost; side-dress when the vines begin to spread or when the first female flowers appear. Full sun means 6 hours of direct light a day at the least, and the plants prefer 8 to 10. Plan on about an inch of water a week, by drip or soaker hose so the leaves stay dry. Black plastic warms the soil for an earlier start, and a row cover keeps off chill and early pests until the plants flower, when it must come off for the bees.

Why zucchini flowers fall off: pollination and fruit set

The first zucchini flowers often drop without fruit because they are male: a squash plant opens only male flowers for its first 1 to 2 weeks, until a female appears, a span that varies with the variety. Fruit comes only from female flowers, and, parthenocarpic varieties aside, only after a bee carries pollen to them.

Telling them apart. A male flower sits on a long, thin stalk; a female grows close to the main stem with a small swelling under the petals that becomes the zucchini. Males usually far outnumber females, by about 3 to 1.

When fruit fails. Misshapen, withered or blackened first fruits, common in some varieties, mean poor pollination and usually clear up as more males open; cold, rainy or cloudy weather can keep bees home. Fixes include patience, well-tended plants, flowers nearby for pollinators, no spraying during bloom, or a parthenocarpic variety, which sets fruit without pollination and can stay under row cover all season.

Hand pollination. If bees are scarce, peel the petals off a male flower and dab its pollen onto the center of each open female.

Picking zucchini: size and how often

Pick most zucchini at 2 inches or less across (1.5 to 2 inches), about 6 to 8 inches long. A fruit is usually ready within 4 to 8 days after its flower opens, so check the plants daily or every few days.

Too big? If your thumbnail cannot dent the rind, the fruit is over-mature. Take it off anyway, since large fruit left on the plant slows the next ones, and never pick from wet vines.

Keeping it. Zucchini keeps from 2 to 3 days in the crisper to up to 2 weeks in a humid cold room at 40 to 50 F, a grower's figure. In a home refrigerator, plan on a few days.

Zucchini blossoms: which flowers to pick and how to use them

Pick zucchini blossoms on the day they open, and take mostly the male flowers: picking males costs you no fruit, as long as you leave a few on the vine for pollination. A female flower is edible too, but each one picked is a zucchini lost.

• Which flower. Male: thin, trim stalk, nothing under the petals. Female: thick stalk with a small zucchini at the base.
• When and where to cut. Cut once the flowers are wide open, in mid to late morning or at midday, leaving 1 to 2 inches of stem below the flower. Pick them just before you cook them, or keep them as described below.
• Before taking every male. Make sure the open females are pollinated first, by hand if need be.

Keeping and cooking. Rinse the flowers gently and hold them in ice water in the refrigerator, where they last a few hours, or at most 1 or 2 days. Try them stuffed and fried, or sliced into soups, omelets, salads and pasta.

Italian zucchini types: Costata Romanesco, cocozelle and Caserta

The Italian marrows include zucchini, cocozelle and Caserta, long squash usually in shades of green. The one to know for blossoms is 'Costata Romanesco': ribbed, gray-green fruit with a nutty flavor raw or cooked, ready in 52 to 60 days. It is a choice variety for edible flowers and a good producer of male blossoms. Its habit is described both ways, as semi-vining and as a bush.

Lost zucchini to vine borers before? Our squash and pumpkins guide covers tromboncino, a long Italian squash it suggests where borers kill zucchini.

Growing zucchini in containers

Summer squash fits the container class of at least 4 to 6 gallons with 8 to 12 inches of depth, so a zucchini plant can grow in a pot that size. Not all advice agrees: zucchini also appears among the crops better suited to the ground than to a pot.

Both can be right. 'Costata Romanesco' is listed at 48 inches wide, yet it is also rated good for containers. In a pot, choose a compact bush type, go large, water often, and make sure of drainage holes; gravel in the base does not help.

Squash vine borer, squash bugs and powdery mildew on zucchini

Squash vine borer. A zucchini that wilts suddenly, even in the morning, likely has a borer in its stem; look for holes with sawdust-like frass at the base. In Minnesota the moths appear in late June or early July and lay eggs at the base of the plant; larvae hatch in about a week and feed inside the stem for 4 to 6 weeks. Timing advice depends on region:

• Where the moths fly from late June. Set out a yellow pan of soapy water by late June and cover bush plants with floating row cover until about two weeks after the first moth (off at flowering), but not where squash grew last year, since moths emerging from that soil end up trapped under the cover. A second sowing in early July matures after the egg laying is over.
• South Carolina. Plant early instead, because borers are a problem later in the season.
• Anywhere. At the first wilt, slit the stem, kill the larva and mound moist soil over the cut. Bt does not work against this borer.

Squash bugs. These large, flat, grayish bugs suck sap and leave yellow spots that turn brown, worst on seedlings and flowering plants; females lay clusters of about 20 eggs under the leaves. Crush the eggs, drop bugs into soapy water and trap them under boards overnight; insecticides are normally not needed.

Powdery mildew. From midsummer, older leaves grow white, powdery patches, favored by humid weather around 68 to 81 F and by crowded, shaded or overfed plants. Grow a resistant zucchini such as 'Payroll' or 'Sebring', water by drip and remove infected leaves; growing squash in the same spot only once every 3 to 4 years can help. Spraying is usually not warranted in a home garden.

What to plant with zucchini

In studies, a border of blue Hubbard squash can pull squash bugs away from the crop, though that border still needs egg squashing or spraying. Nasturtium beside squash has research behind it too, since it can help lower squash bug numbers, and marigolds help cut squash bug and cucumber beetle damage. Evidence for each: our companion planting chart.

Seeds and supplies

Choose 'Costata Romanesco' for blossoms, a parthenocarpic variety for a bee-poor garden or one kept under cover, and a mildew-resistant zucchini where powdery mildew recurs; add a soil thermometer, floating row cover, shears and gloves, and a large pot with drainage holes for a patio.

Sources we used

Behind the figures above are these pages, all read in October 2026. Where two of them disagree, you see both numbers or the range between them.

• University of Minnesota Extension: "Growing summer squash and zucchini in home gardens", "Squash vine borers", "Squash bugs" and "Powdery mildew of cucurbits"
• "Illinois Extension: Summer Squash"
• University of Maryland Extension: "Growing Summer Squash (Zucchini) in a Home Garden" and "Types of Containers for Growing Vegetables"
• "Penn State Extension: Container Vegetable Gardening, Four Keys to Success"
• "Oregon State University Extension: How can I eradicate powdery mildew?"
• "NDSU Extension: Field to Fork, Summer Squash"
• "University of Saskatchewan: Pan fried squash blossoms"
• Companion pairs: "University of Minnesota Extension: Companion planting in home gardens" and "University of Maryland Extension: Vegetable Succession and Companion Planting"
• Johnny's Selected Seeds: "Zucchini Key Growing Information", its "Summer Squash Production" tech sheet and its 'Costata Romanesco' listing
• 'Costata Romanesco' listings from "Botanical Interests" and "Hudson Valley Seed Company"
• Clemson Cooperative Extension: "HGIC 1321, Summer Squash"
• "NOAA NCEI: U.S. Climate Normals, 1991-2020", behind the zucchini calendar

Related guides

• Strawberries in pots and towers, another crop for a sunny container
• Building a raised garden bed; summer squash is among the crops that thrive in one
• Squash and pumpkins, for winter squash, pumpkins and tromboncino
• How to grow melons, another vine crop that needs bees
• How to grow tomatoes, for the same warm beds
• How to grow okra, another crop to pick every day or two
• How to grow cucumbers, a vining cucurbit to grow alongside
• Cucurbits, the family overview with its shared vine borer and mildew notes

Frequently asked questions

How long does zucchini take to grow?

Roughly 50 to 65 days to the first harvest (50 to 65 from transplanting; 52 to 60 from sowing for 'Costata Romanesco'), then usually 4 to 8 days from each flower to its fruit.

How far apart should zucchini plants be?

Most advice gives 18 to 36 inches between plants and 3 to 6 feet between rows; the closest spacing given is 8 to 12 inches, with two or three feet left open beside the row for the vines.

Why are my zucchini flowers falling off with no fruit?

Early blooms are males, which simply fall off; females follow 1 to 2 weeks later, and if they drop too, bees may not be reaching them, so pollinate by hand.

Which zucchini flowers can you eat?

Both, but pick mostly males on the day they open and leave a few for pollination.

What size should you pick zucchini?

For most varieties, at about 6 to 8 inches long, no more than 2 inches across, checking daily or every few days.

Can you grow zucchini in a pot?

It can: summer squash fits pots of at least 4 to 6 gallons, 8 to 12 inches deep, though zucchini also appears among the crops that do better in the ground. Choose a compact bush type and a large pot.

Why did my zucchini plant wilt and die suddenly?

Most often a squash vine borer larva tunneling in the stem; look for holes with sawdust-like frass at the base. Next year, where the moths fly from late June, sow a second crop in early July so it matures after they have laid their eggs, or plant early where borers come later in the season, as in South Carolina.

How do you stop powdery mildew on zucchini?

Space plants for airflow, water at the base, remove infected leaves and grow a resistant variety; sprays are usually not warranted in a home garden.