Tips for Growing Cushaw Squash

Cucurbita argyrosperma

If you get starry eyed at the thought of oversized garden vegetables, cushaw squash will not disappoint.

Grown on vigorous vines, cushaw squash fruits are large and delicious.

And since you won’t likely find them on offer at the grocery store or farmer’s market, make sure to save a spot in your garden so you can grow your own!

Producing crookneck-shaped fruits that weigh 10 to 20 pounds each and reach a foot to a foot and a half in length, cushaws are appreciated for their meaty, moist, and slightly sweet yellow to orange flesh.

It’s ideal for transforming into savory and sweet dishes alike.

And since they can be harvested young or allowed to mature for winter storage, cushaw provides a flexible and long-lasting food source.

In our guide to growing winter squash, we cover the basics of how to cultivate these cucurbits in your garden.

Are you ready to learn the specifics for how to grow cushaw squash? Here’s what we’ll cover:

Cushaw squash (Cucurbita argyrosperma) were domesticated several thousand years ago in Central America.

Eventually they made their way north where they have long been used by Native Americans in the southern part of the US.

Also known as kershaw and sweet potato pumpkin, in the present day cushaw squash remains an important food in southwestern Native American, southern Appalachian, and Louisiana Creole cuisines. 

In fact, this member of the cucurbit family is considered one of the best types of winter squash for cooking.

Cushaws resemble crookneck squash, with narrow, curved “necks” and bulbous bases.

How to Sow

These plants require warm temperatures to thrive, so don’t sow or transplant until after the last spring frost.

You can choose to start your seeds indoors to get a jump on the growing season, or direct sow outdoors, after all risk of frost has passed.

To direct-sow outdoors:

1. First remove any vegetation from the growing area, then mix a few shovels of compost into the soil. Water the planting area the day ahead of sowing.
2. Make a mound of soil in which to plant the seeds unless you’re gardening in an arid climate.
3. Poke two to three one-inch-deep holes in the center of the planting area. Drop one seed into each hole, then cover with soil and pat it down to ensure good contact.
4. Water directly after sowing, and daily if needed, to keep the soil evenly moist until germination. Expect germination in five to 10 days.
5. If more than two seeds germinate successfully, remove the weakest seedling in each mound.

In addition to seeds, you will need suitable growing medium and three- to four-inch biodegradable seed starting pots or celled trays.

1. Moisten the growing medium and fill the pots or trays, leaving about an inch gap at the top so that you can water without the medium spilling out.
2. Insert one seed an inch deep in the center of the pot or in each cell, closing the medium over the seed and patting it gently.
3. Situate the pots or trays where they will be exposed to six to eight hours a day of direct sunlight, or the equivalent from grow lights.
4. Keep the soil at a temperature of 70 to 95°F, using a heat mat if necessary. After germination, remove the supplemental heat.
5. Keep the growing medium evenly moist.

Wait until the last frost date has passed, then harden off the seedlings before transplanting to acclimate the young plants to outdoor weather conditions.

Transplanting

Transplant your cushaw seedlings on a cloudy day or wait until the heat of the day has passed to avoid planting under bright sun or in intense heat.

1. Clear the patch or raised bed of vegetation and dig a hole twice as wide and deep as the seedling pot, then add water to the hole.
2. If growing in a biodegradable pot, remove the rim and insert the entire pot into the hole.
3. For seedlings in plastic nursery pots, squeeze the pot to ease out the root ball, then place the root ball into the hole.
4. Backfill with soil, and pat down to remove large air pockets.

Water the newly transplanted seedlings at the soil level, and keep them evenly moist while they become established.

How to Grow

If you’ve never grown winter squash before, you’re in for some gardening fun. Here’s what you’ll need to know about these fast growers:

Climate

Cushaw squash are sensitive to frost so plants will be damaged or killed when temperatures drop below freezing.

Light

Are you wondering if you have enough sunlight to grow cushaw squash? The plants need a full sun location, which means six to eight hours of direct sunlight per day.

Soil

Cushaw squash thrive in typical garden soil with a loamy texture and a pH range of 6.0 to 7.0.

The plants prefer soil that has lots of organic matter – so don’t forget to work some well-rotted compost into the soil before sowing seeds or transplanting.

Water

How often to water will depend on your weather, climate, and other growing conditions, so keep in mind that cushaw squash likes moist soil – but not soil that is soggy or waterlogged.

You can apply a layer of mulch around the plants to help keep weeds down and retain moisture.

Fertilizing

You don’t need to apply fertilizer to your cushaw squash, especially if you worked compost into the soil at planting time.

Once or twice during the growing season, side dress with additional compost to give the plants a nutrient boost.

Cultivars to Select

Ready to pick a cushaw for your garden? Here are some of the most popular varieties:

Cushaw White

Also known as ‘Jonathan Pumpkin,’ ‘Cushaw White’ has white skin and sweet, pale orange flesh.

The fruits of this heirloom weigh in at 20 to 30 pounds and reach maturity in 85 to 110 days.

‘Cushaw White’

Pick up some ‘Cushaw White’ seeds in your choice of packet sizes from True Leaf Market.

Green Striped

The green striped cushaw is the most widely grown and popular type of cushaw squash, and it is included in the Slow Food Foundation’s Ark of Taste.

The fruits have light yellow flesh with a medium coarse texture.

The white and green striped fruits of this heirloom reach up to 25 pounds and mature in 90 to 110 days.

Green Striped

You’ll find an assortment of packet sizes of green striped cushaw seeds at Eden Brothers.

Orange Stripe

With fruits reaching up to 30 pounds each, ‘Orange Stripe’ cushaw squash have – as the name suggests – orange stripes on creamy skin, and golden flesh with a fine texture.

‘Orange Stripe’

Head to True Leaf Market for ‘Orange Stripe’ cushaw squash seeds in a variety of packet sizes.

Managing Pests and Disease

Like all winter squash, there are a number of pests and disease problems to contend with during the growing season.

Here’s what you’ll need to watch for:

Herbivores

While a tall fence is needed to keep out deer, you’ll only require a short fence with small mesh to prevent rabbits from slipping through.

Pests

You’ll be happy to know that this particular type has good resistance to squash vine borers. 

However, there remain a few insect pests you’ll need to keep an eye out for:

Cucumber Beetles

Small yellow beetles with black stripes or spots on their backs, cucumber beetles are so cute it’s almost hard to be mad at them when they start chewing up your garden plants.

Not limiting themselves to cucumber plants, these beetles will also feed on other members of the cucurbit family – including cushaw squash.

In addition to damaging plants directly, these pests can also spread diseases, providing you with an unwanted, two-for-one pest and disease special.

Learn how to manage cucumber beetles here.

Spider Mites

Are there tiny discolorations on the foliage that makes the leaves look faded and slightly pale? This could be stippling from spider mites.

These pests can often be removed with a hard spray of the garden hose.

Our guide to controlling spider mites has more information.

Squash Bugs

Squash bugs can feast on cushaw vegetation, which damages and can eventually cause the plants to die.

The best way to deal with these pests is to pick them – and their eggs – off by hand.

Lift the leaves and check the undersides where the small, shiny, orange or bronze eggs are usually hidden – and destroy them to prevent new broods.

As for the adults, they are easy to see when watering, and their young are recognizable by their light green or bright gray bodies and skinny black legs.

You can also keep pest populations down by using companion plants to attract beneficial insects.

Learn more about squash bugs here.

Disease

There are several diseases that commonly affect these cucurbits. Here’s what to look out for:

Blossom-End Rot

If the fruits are rotting on the vine rather than growing ever larger, consider blossom-end rot as the likely problem.

Read about blossom-end rot in zucchini for guidance.

Squash Mosaic Virus

Causing distorted leaves and a yellow mosaic pattern on foliage, squash mosaic virus is spread by insects such as cucumber beetles.

If you suspect that mosaic virus is affecting your crop contact your local cooperative extension to verify the problem since herbicide injury can cause similar symptoms.

If mosaic virus is indeed the issue, remove and destroy all affected plants and debris – don’t compost it to avoid spreading the disease.

Powdery Mildew

Do your plants look like they were dusted with flour?

Powdery mildew is a fungal disease that occurs when weather is humid but mild. It’s extremely common and easy to treat.

Our guide to powdery mildew control has all the details.

Harvesting

You can enjoy cushaws as a summer squash by harvesting early, while the young fruits have soft rind.

To harvest, grab a clean knife and cut through the stem, in the same way you would harvest zucchini.

Preserving

There are various ways to preserve these vegetables, you can choose from cool storage, pickling, freezing, dehydrating, and canning.

You can store these cucurbits for up to six months in a cool location such as an unheated basement, garage, or a root cellar.

And be sure to use a pressure canner! Need more guidance on this method?

Find tips for pressure canning on our sister site, Foodal.

You can also pickle cushaw squash, which can either be canned or lacto-fermented for healthful, probiotic benefits. You can also dice some up and add it to a lacto-fermented salsa.

Need a recipe? Head to our sister site, Foodal for guidance on making a homemade lacto-fermented salsa.

Need to freeze some leftover cushaw? First cook the flesh until soft, then store it in your favorite freezer safe container for up to a year.

And if you want to transform your harvest into a snack food or pantry staple for adding to winter soups, you can also consider dehydrating some of the flesh.

Our guide to dehydrating garden produce has more information.

Cooking Ideas

Use cushaw squash as a substitute for any recipe that calls for winter squash or pumpkin.

In southern Appalachia, these vegetables are used to make cushaw butter (similar to pumpkin butter) as well as pie filling.

If you need a pie recipe, why not borrow this pumpkin pie recipe from our sister site, Foodal and make it with cushaw? Oh and by the way, it’s vegan.

Or how about a savory snack? Add cooked cushaw squash to hummus, following this recipe, also on Foodal.

And since your cushaw harvest will have you craving autumn flavors, why not try an earthy and warming meal of roasted squash with black rice and miso dressing?

You’ll find the recipe on Foodal.

Cheers to Our Copious Cushaws

After reading this guide, you should be all set to grow these extra-large winter keepers!

Do you have a special connection to the fabulous cushaw? Or are you growing them simply for the pleasure of trying something new?

Let us know in the comments section below. And if you have any remaining questions, feel free to drop them there as well!

Want to keep learning about growing squash in your garden? We have more reading for you right here: