Wondering how to grow winter squash? You’ve come to the right place. Are you also wondering why it’s called “winter” squash when it grows throughout the summer? Winter squash, unlike summer squash, develops a thick rind that increases its storage life, with many types of winter squash storing well through the winter.
Another distinguishing characteristic of winter squash is it has a separate seed cavity (think of a pumpkin – one of the most famous winter squash), not like summer squash whose seeds are distributed throughout the fruit.
An added difference is the flavor of winter squash improves as it grows and cures, while summer squash tastes best when harvested young.
On the whole, learning how to grow winter squash is pretty similar to growing summer squash, but whatever you do for summer squash you’ll need to do more of it for winter squash. Winter squash needs more room, more time, more water, and more food to grow well.
1. Give winter squash plenty of time to grow
Winter squash needs 3 months or more of frost-free temperatures. Both the fruit and the vines are frost sensitive. Plant seeds directly in the garden 1-2 weeks after the last frost.
In short-season areas (usually zone 6 and cooler), start seeds indoors 2-3 weeks before planting. Do not let seedlings get pot bound; transplant very carefully once soil warms up.
In the low desert of Arizona, there are 2 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 early August. Established fruit on winter squash will ripen in temperatures up to 100℉, but pollen 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:
2. Plant different varieties depending on your situation
There are dozens of varieties of winter squash; choose the best one for your location, tastes, and garden size.
- Not a lot of room? Try bush or more compact varieties. My favorite bush type: Gold Nugget.
- Shorter growing season? Grow smaller types and look for varieties with shorter days to harvest. My favorite short-season winter squash: Delicata.
- Not a fan of the taste or texture of certain types? Be familiar with the tastes, and grow one you like to eat! My favorite type to eat: Butternut.
- Have pests and diseases been a problem in the past? Choose resistant varieties such as Acorn Squash.
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 hammock or melon holder.
- 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.
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. Give winter squash plenty of food throughout the growing season
Plant winter squash in rich, well-draining soil amended with plenty of compost. Work plenty of compost into the soil. Amend soil before planting with liquid seaweed fertilizer. When plants begin to blossom and set fruit, give a good feeding of a liquid organic fertilizer. Feed plants every 2-3 weeks throughout the growing season with a compost tea or other liquid organic fertilizer.
6. Be patient when waiting for the ladies to appear
Male blossoms have a single long stem at the base of the flower, while female blossoms have a small swollen fruit at the base of the flower. Male blossoms appear first – usually in large numbers. They will be followed in a few days or weeks by the female flowers.
Once the ladies arrive, consider hand pollinating if a lack of pollination has been a problem in the past. Hand pollinate female blossoms by carefully removing a male blossom, peeling back the petals, and transferring pollen from the male to the stigma of the female blossom.
7. Stay ahead of common pests and diseases
Healthy soil and plants are the best defense against pests and disease. Here are a few tips to keep your winter squash pest and disease free:
- 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.
- Diatomaceous earth is an effective organic option against many winter squash pests.
- 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.
- Observe plants daily for signs of squash bugs, borers, and cucumber beetles. Handpick bugs and dispose of eggs.
- 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.
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 10 days after harvesting. Sunshine toughens skin and makes fruit sweeter. If frost makes curing outside impossible, let winter squash cure by a sunny window in your home for 2 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. Observe squash during storage, and use or dispose of any soft squash right away.