WHEN TO PLANT SQUASH – PLANTING GUIDE 2021

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when to plant squash

We have so many squash options, you can plant squash almost throughout the year. But there are guidelines you will need to follow.

Our 2021 planting guide will help you identify where, when, and how to successfully plant squash in your home garden. 

The leading question is when to plant squash? The short answer is to plant winter squash in mid-summer, and summer squash and zucchini in spring when there is no danger of frost. But the best time will always depend on your location, climate, and seasonal weather conditions. 

Planting Squash in Different Climates

Both winter and summer squash are warm season plants. They don’t do well in cold weather. 

Both climate classifications and defined gardening planting zones will help you to determine whether squash will grow well where you live. 

Planting Zones

Generally, squash grows best in the U.S. planting zones 3-10. 

Zone 1 is the coldest zone with an average minimum temperature in winter of -60 to -50°F (-51 to -46°C). Zone 2 has average minimums between -50 and -40°F (-46 to -40°C). 

Squash isn’t going to survive outside in these zones, but you can grow squash in a greenhouse.

Planting Zones 11 and higher are as hot as Zones 1 and 2 are cold. Zone 11 has average minimum temperatures between 40 and 50°F  (4.5 and 10°C).

While squash is a warm season plant, it’s not going to do well in such warm environments. 

Different Climates

Köppen, the best-known climate classification system, divides global climates into five main groups:

  1. Tropical
  2. Dry
  3. Temperate
  4. Continental
  5. Polar  

Generally, if your growing season is short, opt for bush squash varieties and summer squash that will mature more quickly. 

Overall, you will have the best success in a temperate climate. 

Choosing Squash Seeds

choosing squash seeds

Your initial choice will be between winter squash and summer squash, both of which are the Cucurbita species. Winter squash has a much longer growing season than summer squash, which is harvested when the fruit is immature. 

It’s not called winter squash because it grows or is harvested in winter. Rather, it’s because the fruit has a long shelf life and stores well during the cold winter months! 

The most common winter types of squash include: 

  • pumpkins
  • Hubbard squash
  • acorn squash (Cucurbita pepo)
  • spaghetti squash
  • butternut 

Young squash identified as summer squash include: 

  • gem squash
  • crookneck and straight yellow squash varieties
  • pattypan or scallopini squash
  • zucchini, also known as baby marrows 

Genetically Modified Squash Seed

Even though the FDA approved some genetically modified (GM) squashes in 1995, they are grown at low levels in the U.S. You just need to be aware that some seeds, specifically summer yellow squash and zucchini, might be GM.

While the PR claims they are cheaper and potentially more nutritious than non-GM plants, squash plants grown from GM seeds have an altered DNA. They are also linked to all kinds of health issues. 

But that’s not the only issue. When farmers grow GM seeds, they are not allowed to save the seeds from plants and grow them the following season.

This has huge implications for the farming industry as a whole. It will also impact you if you decide to buy Monsanto squash seeds. 

That said, if you want to save seeds from non-Monsanto squash you have grown, you are free to do so. 

In any case, nobody’s likely to check if you are growing squash in your backyard. But if there’s a seed law in your state or country, it’s a good idea to be aware of it!

Whatever seed you choose, planting guidelines are universal. 

How to Plant Squash Seeds

Before you plant squash seeds, you need to select a suitable growing site and make sure that the soil is right. Young squash plants need full sun to thrive, so make sure they will get at least 6 hours of sunshine daily.  

Squash generally grows best in fertile but sandy soil with a pH between 6.0 and 6.5. It’s usually a good idea to dig in organic matter like compost, rotted hay, or even fallen leaves. 

A 10-10-10 fertilizer is also good practice. Work it into the top few inches of soil. 

If you are planning to plant your squash seeds directly outdoors, prepare the beds when the danger of frost has passed. 

They do well if you make slight ridges, rather like rows of hilly raised beds, within the bed. These should be about 3-8 feet (1-2.5 m) apart. 

Ideal Soil and Air Temperatures for Planting Squash Seeds

Make sure that soil temperatures are at least 60°F (16°C) so that the seeds don’t rot before they germinate. The ideal temperature for maximum germination is between 65 and 85°F (80-30°C). 

Plant 5-6 seeds of bush-type squash in small circles about an inch (2.5 cm) deep and 1.5-2 feet (a bit more than half a meter) apart. Sow seeds of squash vines the same way but about 4 feet (1.2 m) apart. 

You will need to thin out the little plants later so that the plants are about 18-36 inches (46-90 cm) apart. 

In colder areas, you can give your seeds a head start by planting indoors. Do this 2-4 weeks before the last frost date.

Remember that the growing season for squash stretches from the last frost date until the next year’s first frost date. Technically, the frost date is when temperatures fall below 32°F (0°C). 

Where Not to Plant Squash Seeds

A final warning. Squash spreads fairly rampantly and should not be planted near root vegetables like onions, potatoes, beet, and carrots that might damage the young squash roots when they are harvested.  

How to Water Squash

how to grow squash

Your local weather conditions will determine how often you water your squash plants. You need to water enough to prevent them from wilting, but no more than once a week, even when it’s really dry.

How to Grow Squash

Squash is traditionally grown using the Native American growing technique known as the Three Sisters. It’s a type of companion planting that combines corn, beans, and squash in the same garden bed. 

According to the Texas A&M AgriLife Extension horticulturists:

  1. Squash plants become a ground cover that stops weeds from growing
  2. Beans provide natural fertilizer in the bed
  3. Corn becomes a natural structure that the vining beans use for support

We’ve talked about planting squash, but what do you do once your squash grows?

During the growing season, it’s important to keep the ground free of weeds. 

You can hoe around them as long as you don’t damage the roots, but hand pull weeds where you can. Don’t hoe more than one inch deep. 

When the first flowers appear on the plants, fertilize again. Don’t let the fertilizer touch the plants, and water well afterward.

Squash Flowers

Squash is one of those plants that produce female flowers and male flowers on the same plant. They need male and female flowers for pollination.

Since squash flowers are edible, they make a lovely addition to a salad. But if you pick any of the flowers, opt for male rather than female flowers because the females set the fruit. Just don’t pick them all or your flowers won’t pollinate. 

The million-dollar question is how to tell the difference. 

Male flowers develop and open long before the female flowers. Blooming of the two sexes does, though, overlap, allowing pollination and fruiting. 

The male flowers have a narrow stem that is straight and usually at least 2 inches long. The female flowers have a swollen stem that looks a bit like a tiny version of a squash.  

Squash Plant Diseases

Squash plants are most susceptible to diseases when harvesting starts. Prevention is better than cure, so you might need to use an approved fungicide. 

The main baddies to watch out for are:

  • Squash vine borers and their white larvae
  • Squash bugs
  • Cucumber beetles

How to Harvest Squash

Harvest winter squash when it is mature and fully grown. Don’t pull it from the vine, rather cut it with a sharp knife. 

A good rule of thumb is to harvest winter squash when the vines are beginning to die back and you can’t scratch through the skin with your fingernail. 

Harvest summer squash when the fruit (and therefore the seeds inside) are small. You want to be able to eat the skin and the cooked seeds.  

Another reason not to leave the fruit on the vine is that new fruit won’t grow. 

How Long Does Squash Take to Grow?

Most varieties of squash take anything between 80 and 120 days from the day you plant the squash seeds to harvest. 

Winter squash, which takes longer to mature than summer squash, takes 45-55 days after it has flowered. Summer squash can be harvested quite soon after flowering. 

Both winter and summer squash typically takes 35-45 days to flower. But it does depend on the variety of squash you plant and on the local temperatures. 

Conclusion

Whether you prefer winter squash or summer squash, this is a vegetable that deserves some attention. It is a prolific producer and very rewarding in a homesteading environment. 

You can store winter squash for months, and summer squash will keep you and your family fed constantly for weeks on end.

There are lots of different types of squash to choose from. Explore your options and expand your culinary treats. 

Thes best thing about squash is the many ways that you can cook and eat them. You can eat some types raw, you cook many in boiling water and eat with butter, salt, and pepper, and you can stuff other types and make a full meal of them.

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