Growing Squash (Zucchini)

Planting, Growing, and Harvesting Summer and Winter Squash

Growing Zucchini
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Squash, especially zucchini, are outrageously prolific producers! Easy to grow, each plant will produce several squash a day during peak season! Here’s how to sow, grow, and harvest squash. 

Chances are that you’ll end up with more zucchini harvest that you can handle. But that’s OK!  See our recipes below for all the different ways you can enjoy (or preserve) zucchini. Plus, zucchini is full of nutrients! You can’t go wrong…unless you forget to harvest and end up with giant baseball bats! (More on how to harvest later.) 

Squash are generally divided into two categories based on when they’re harvested and how they’re used:

  • Summer squash are warm-season crops harvested in the summer before they reach full maturity. Because they’re harvested early, their skin is edible and they have a relatively short shelf life. Summer squash varieties include zucchini, yellow squash (straightneck squash), and crookneck squash. T

  • Winter squash are harvested in autumn after or just before they reach full maturity. This leaves their skin inedible, but gives them a longer shelf life (some varieties are capable of keeping through the winter—hence the name “winter squash”). Winter squash varieties include pumpkins, butternut squash, spaghetti squash, and acorn squash.

Most summer squash now come in bush varieties, which take up less space, but winter squash are vining plants that need more space. Bush varieties will need to be thinned in early stages of development to about 8 to 12 inches apart.

Thanks to their regular bumper crops, you usually only need one or two zucchini plants—and you may still find yourself giving zucchini away to neighbors or baking lots of zucchini bread!

A Common Ancestor

Would you believe that pumpkins and zucchini come from the same species of plant? That’s right—they’re both cultivated varieties (“cultivars”) of Cucurbita pepo. Despite the great diversity of squash, most commonly-grown cultivars belong to one of three species: Cucurbita pepo, C. moschata, or C. maxima. Over generations and generations, these plants have been cultivated to produce fruit in all kinds of shapes, colors, and flavors. 

Planting Dates for SQUASH (ZUCCHINI)

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Planting Calendar for all Plants

Planting

When to Plant Squash

  • Sow squash/zucchini directly outside at least a week after your last frost date. The soil needs to be warm (at least 60ºF/16°C at a two-inch depth). The Garden Planner will calculate your exact planting dates for squash based on your location.
  • If you wish to start seeds indoors, sow 2 to 4 weeks before your last spring frost in peat pots.
  • Warm the soil with black plastic mulch once the soil has been prepared in early spring.
  • Do not rush. Waiting to plant will avoid problems from squash vine borers and other pests and diseases common earlier in the season.

Choosing and Preparing a Planting Site

  • Pick a spot with full sun, shelter from wind for good pollinations, and well-draining soil. 
  • Squash plants are heavy feeders. Add plenty of garden compost or well-rotted manure to the soil before planting. 
  • When you plant their holes, scatter in some organic fertilizer as well. 

Learn more about soil amendments and preparing soil for planting.

How to Plant Squash

  • Plant seeds in the ground about 1-inch deep and drop in 2 seeds. Pop a clear jar or half a plastic bottle over the top or use a cold frame protection in cold climates. Leave until the seedlings are up, and then remove the jar, and remove all but the strongest seedling. 
  • Alternatively, plant as a “hill” of 3 or 4 seeds sown close together on a small mound; this is helpful in northern climates, as the soil is warmer off the ground. Allow 5 to 6 feet between hills.
  • If you wish to get a head start: Sow under cover in a greenhouse a couple weeks earlier. Fill small pots or seed trays with potting mix and sew one seed in each pot. Prepare small plants for life outdoors by “hardening off.”  Set the pots outside for a week or two for a short time and increase the length of time. Plant after no risk of frost.
  • Plant squash at least 2 feet apart. (The Garden Planner will calculate spacing for you.)
  • Thoroughly water after planting.
  • Adding a layer on top of mulch or organic matter can help lock in soil moisture.

Demo: See How to Grow Zucchini and Summer Squash

Demo: See How to Grow Winter Squash

Care

How to Grow Squash

  • Mulch around plants to protect shallow roots, discourage weeds, and retain moisture.
  • When the first blooms appear (which will be male flowers), apply a small amount of fertilizer as a side dress application.
  • If your weather is cool, damp, or you’re not seeing pollinators, you can hand pollinate your squash blossoms.
  • For all types of squash, frequent and consistent watering is important for good fruit development. Water most diligently when fruits form and throughout their growth period.
  • Water deeply once a week, applying at least one inch of water. Do not water shallowly; the soil needs to be moist 4 inches down.
  • After harvest begins, fertilize occasionally for vigorous growth and lots of fruits.
  • If your fruits are misshapen, they might not have received enough water or fertilization.

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Pests/Diseases

Powdery Mildew can be an issue on the leaves later on in the season. Keeping plants well-watered and leaving plenty of space between them for good air flow should slow the spread of this disease. If your squash does get powdery mildew, don’t worry about it; plants will usually cope.

There are few challenging insect pests. The best solution is to get ahead of them before they arrive. Click on the links below to learn more.

Blossom-End Rot is an occasional issue. If the blossom ends of your squash turn black and rot, then your squash have blossom-end rot. This condition is caused by uneven soil moisture levels, often wide fluctuations between wet and dry soil. It can also be caused by calcium levels. To correct the problem, water deeply and apply a thick mulch over the soil surface to keep evaporation at a minimum. Keep the soil evenly moist like a wrung out sponge, not wet and not completely dried out.

Harvest/Storage

Havesting Summer Squash

Begin harvesting zucchini and squash when the fruits are quite small (about 6 to 8 inches) Smaller fruits are more tender and flavorful with a denser, nuttier flesh. Believe us, smaller fruits have a far superior taste. If you have ever had a negative experience with zucchini before, it’s probably because they were left to become bruisers.

Please, please, please check every day once zucchini gets going. Plus, picking frequently can lead to a larger crop.

  • Most varieties average 60 days to maturity, and are ready as soon as a week after flowering. (Check the seed packet for more exact information.)
  • Cut your squash from the vine with a sharp knife rather than breaking them off. Leave at least an inch of stem on the fruit.
  • Should you miss a picking or two, remove the overripe squash as soon as possible to reduce demands on the plants for moisture and nutrients.
  • Summer squash is very susceptible to frost and heat damage, so you do want to pick them all before the first fall frosts arrive.
  • Store unwashed in the refrigerator until you’re ready to use. Fresh summer squash can be stored in the refrigerator for up to ten days.

Harvesting Winter Squash

  • Harvest winter squash when the rind is hard and deep in color, usually late September through October.
  • Winter squash can be stored in a cool, dark place until needed. Many varieties will last for most of the winter (except for acorn squash, which do not keep for more than a few weeks). If you have a cool bedroom, stashing them under the bed works well. They like a temperature of about 50 to 65°F (10 to 18°C).
  • Pull up the vines and compost them after you’ve picked everything or after a frost has killed them. Then till the soil to stir up the insects a bit.

Recommended Varieties

Wit & Wisdom

  • Squash flowers are edible and make a tasty treat when fried in a light batter.
  • Pumpkins and other squashes are nutritional powerhouses! Learn about squash’s health benefits.

Recipes

Cooking Notes

There are so many ways to use your nutritious, tasty zucchini!  From Zucchini Bread to Zucchini Gratin to Fried Zucchii, check out some of our many Almanac recipes!
Zucchini Bread recipe by Paula Deen

If you find yourself with a bumper crop, squash pickles are easy to make, too.

Or, freeze your squash! Wash it, cut off the ends, and slice or cube the squash. Blanch for three minutes, then immediately immerse in cold water and drain. Pack in freezer containers and freeze. Learn more tips for freezing zucchini.

See more of our Best Zucchini Recipes for ways to use this abundant crop!

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Growing Squash (Zucchini)

Botanical Name Cucurbita
Plant Type Vegetable
Sun Exposure Full Sun
Soil Type Loamy
Soil pH
Bloom Time Summer
Flower Color Orange, Yellow
Hardiness Zones Varies
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