How to Grow Winter Squash
Growing winter squash used to intimidate me, but it has become one of my favorite crops after successfully growing it for several seasons. I’m sharing my best tips for successfully growing winter squash, even in hot climates like the low desert of Arizona. In this article, you will learn how to grow winter squash, which varieties to choose, how to care for your plants, and the best times to harvest.
A little bit about winter squash
Have you ever what the differences are between winter squash and summer squash?
- Unlike summer squash, winter squash has a thick rind that allows it to be stored for longer periods of time. Many types of winter squash can last well into the winter months.
- Another distinguishing feature of winter squash is its separate seed cavity, similar to a pumpkin, one of the most well-known types of winter squash. In contrast, summer squash has seeds distributed throughout the fruit.
- Additionally, the flavor of winter squash improves as it grows and cures, while summer squash is best eaten when harvested young.
- Although growing winter squash is similar to growing summer squash, more attention is needed. Winter squash requires more space, time, water, and food to grow well.
9 Tips for How to Grow Winter Squash
1. Give winter squash plenty of time to grow
Winter squash needs three months or more of frost-free temperatures. Both the fruit and the vines are frost-sensitive. Plant seeds directly in the garden one to two weeks after the last frost.
Ensure the soil is warm before planting the seeds – about 65°F (18.3°C) or higher, generally, at least two weeks after your last spring frost date.
- Plant the seeds ½ in (1.27cm) deep and at least 8 in (20cm) apart, then water them daily until they sprout.
- Winter squash may require a long growing season (90+ days) depending on the variety. If you have a short growing season or would rather start seeds indoors. Plant seeds in 4 in(10cm) pots 2-4 weeks before your outside planting date. Do not let seedlings get pot-bound; transplant very carefully once the soil warms up.
- Read this post for more information about starting seeds indoors.
In the low desert of Arizona, there are two planting widows for winter squash. Plant winter squash early in the spring, from mid-February to March, and again when the monsoon moisture comes in July and August.
Established fruit on winter squash will ripen in temperatures up to 100℉, but pollen often won’t be viable to produce new fruit. Choose smaller types and short-season varieties for the best chance of success when growing winter squash in Arizona.
A note about how to grow pumpkins in Arizona:
Regular-sized pumpkins may be planted in either February or March or again when the monsoon moisture comes in July and early August.
Pumpkins planted in February or March should be ready to harvest in May or June. Pumpkins planted in July and early August should be ready by October or November.
If you are trying to grow super-sized pumpkins in Arizona, plant the seeds in early January. Provide protection from frost, mulch well, fertilize regularly, and provide shade throughout the summer.
Looking for pumpkin seeds?
Pumpkins are a type of winter squash. Follow the winter squash planting tips below to grow pumpkins.
2. Plant different varieties depending on your situation
There are dozens of varieties of winter squash; choose the best one for your location, taste, and garden size.
Not a lot of room? Try bush or more compact varieties. My favorite bush type is Gold Nugget.
Shorter growing season? Grow smaller types and look for varieties with shorter days to harvest. My favorite short-season winter squash is Delicata.
Not a fan of the taste or texture of certain types? Become familiar with the tastes, and grow one you like to eat! My favorite type to eat is Butternut.
Have diseases been a problem in the past? Choose resistant varieties such as Acorn Squash.
“Baby” Spaghetti Squash – a smaller variety with a short “days to harvest”
What about gourds?
Gourds and winter squash have distinct differences in their usage, appearance, edibility, growing season, and shelf life.
- Gourds are generally used for decorative purposes, have a bitter taste, and come in various shapes.
- On the other hand, winter squash is edible, has a delicious flavor, and is more consistent in appearance.
- Generally, gourds take longer to grow and have a longer shelf life than winter squash.
Birdhouse gourd – an ornamental gourd.
Cucuzza gourd – an edible gourd. Learn more about how to grow cucuzza gourd in this article.
3. Give winter squash room to grow
Plants grow large and can quickly take over a garden. Grow winter squash along the edge of the garden so they can spill outward. Direct growing vines away from other plants as they grow.
Additionally, train vines up tall ladders and arbors; get creative and find ways to give the growing vines plenty of room and airflow. When grown vertically, larger fruit will benefit from some sort of melon cradle.
- Choose a location to grow winter squash that gets 6-8 hours of sun.
- The soil should be loose to a depth of 1 foot.
- Rotate each year where you plant to help prevent pests and diseases. Do not plant in the same place that other squash, cucumbers or melons were the previous season.
- Sow 2-3 seeds about an inch deep.
- Sow seeds in hills at least 2 feet apart, preferably up to 4-5 feet apart.
- Thin to the strongest seedling when plants are 2-3 inches tall by snipping other plants. Never pull on the roots as it may disrupt the other seedlings.
- If using square foot gardening, plant winter squash on the outside edge of a bed allowing 2-4 square feet per plant.
Looking for ways to add vertical space to your garden? This post shares 10 of my favorite ideas.
In this blog post, find more ways to add vertical space to your garden.
4. Supply winter squash with plenty of water
Winter squash plants are happiest with heavy and even watering. Winter squash are typically big plants with big fruit that need a lot of water.
- Once plants are 3-4 inches tall, mulch plants well to hold in moisture.
- Water slowly and deeply once the top 2 inches of soil has dried out.
- Water the soil (not the leaves and vines) to help prevent powdery mildew.
- Leaves may wilt in the afternoon sun but recover once temperatures cool. This is heat stress, not water stress.
- If squash leaves are wilted in the morning, they need water as soon as possible.
5. Feed winter squash regularly
Plant winter squash in rich, well-draining soil amended with plenty of compost. Work plenty of compost into the soil. When plants begin to blossom and set fruit, feed them with a liquid organic fertilizer or organic granular fertilizer. Feed plants about once a month during the growing season.
6. Be patient when waiting for female blossoms, and hand-pollinate if necessary
Each winter squash plant develops male and female flowers. The way to differentiate between male and female blossoms is by looking at the base of the flower. Male blossoms have a single long stem, while female blossoms have small swollen fruit.
Typically, male blossoms appear first and in large numbers, followed by female blossoms in a few days or weeks.
If you find female fruits are withering and not developing into fruit, consider hand pollinating the female blossoms. This can be done by carefully removing a male blossom, peeling back the petals, and transferring the pollen to the stigma of the female blossom.
7. Stay ahead of common pests and diseases
Healthy soil, planting at the right time, correct watering, and keeping your plants healthy are the best defenses against pests and diseases. Here are more tips to keep your winter squash pest and disease free:
- Check the underside of leaves daily for signs of squash bugs, borers, and cucumber beetles. Handpick bugs and dispose of eggs.
- Grow plants vertically, or use plant supports to keep them up off the ground to prevent pest damage.
- Allow enough room for plants to grow freely; good air circulation helps prevent powdery mildew. At the first sign of mildew, remove affected leaves and spray with a sulfur or baking soda solution.
- Use row covers when plants are young to protect against insects.
- Plant radishes around the plant to deter pests; allow the radishes to flower and remain in place throughout the season.
- Other companion planting ideas that can be mutually beneficial and help with insects include borage, oregano, marigolds, nasturtium, lemon balm, corn, and beans.
- Keep the garden picked up and free from debris that may harbor pests and diseases.
8. Harvest winter squash correctly
Winter squash should be allowed to stay on the vine until fully mature. Winter squash is ready to harvest when the skin of the squash cannot be dented with a fingernail and when the stems shrivel and begin to die.
Do not leave the fruit on the plant too long, or it may split.
If you live in an area with frost, harvest before the first hard frost. If there is a light frost, harvest all fruit right away.
Cut the fruit from the vines leaving 2-3 inches of stem. Do not carry fruit by the stem, as it may break off. Squash without stems does not store as well.
9. Cure and store winter squash properly
Leave winter squash on the ground to cure for about ten days after harvesting. Sunshine toughens the skin and makes fruit sweeter. If high heat or frost makes curing outside impossible, let winter squash cure by a sunny window in your home for two weeks.
Wipe dirt off fruit, but do not spray off. If desired, use a Clorox wipe to lightly wipe off to help prevent rot during storage. Store in a cool, well-ventilated area for up to 6 months.
Check squash frequently during storage. Use or dispose of any soft squash right away.
I planted calabeza squashes in March, but they are growing beyond 10 feet on a trellis and not flowering(I grew 9 varieties, these are the only ones that haven’t flowered or fruited. Should I uproot them and start over?
I’m having the same issue this year with a Red Kuri squash…. long vines but no fruit. I’m going to leave mine and see what happens because the vines are happy. You could always plant new seeds next to the vine and give it more time to see if it begins to fruit before the other vine takes off.
I’m new to AZ gardening and have been following all of your sites! Love them and thank you for the knowledge and courage. My son asked me if I could plant pumpkins for Halloween. I have room, not a ton, but would love to be able to accommodate his wishes. A small traditional pumpkin that can be set out or carved for Halloween. Any recommendations would be greatly appreciated. I’m in Glendale. Thanks!!
Look for small varieties, they are easiest to grow. This one from Johnny’s looks good. https://www.johnnyseeds.com/vegetables/pumpkins/specialty-pumpkins/pipsqueak-pmr-f1-pumpkin-seed-4019.html#q=pumpkin&prefn1=disease_resistance_codes&prefv1=Powdery+Mildew&prefn2=prod_feature_marketing&prefv2=8&start=1
@Angela Judd, Thank you so much! In reading the “when to plant” it says spring. I am assuming that does not mean here in AZ. When do you think I should plant these? In reading your article there is a possibility I could plant in July/Early August. And finally, I was thinking a barrel planting or large grow bag, OR – do you think they would grow better in my raised bed. Thank you again for all of your knowledge and inspiration.
I’ve got some sugar pumpkins growing right now and have noticed some of the newer leaves are a pale greyish green compared to previous leaves. When I rub my thumb on the leave nothing wipes away, so I don’t think it’s mildew and there’s no obvious pests. Any thoughts on what could be causing it?