How to Grow Butternut Squash

Learn how to grow Butternut squash. This post covers all the steps, from planting the seeds to picking a beautiful squash. Butternut squash, scientifically known as Cucurbita moschata, has a sweet, nutty flavor (similar to a pumpkin) and is one of my favorite crops to grow. It’s a warm-season vegetable that requires a long growing season to mature and grows very well in the low desert of Arizona.

Try different varieties of butternut squash

Butternut squash plants are vigorous and can grow up to several feet long, producing fruits weighing up to several pounds. Butternut squash is known for its high vitamin A and potassium content, making it a nutritious addition to your diet.

There are many varieties of butternut squash to choose from, each with unique characteristics. Here are some of the most popular:

• Waltham Butternut: This classic variety has a sweet taste and smooth texture.
• Butterbush: This smaller variety is ideal for container gardens or small spaces.
• Early Butternut: This variety matures earlier than other butternut squash, making it a good choice for regions with shorter growing seasons.
• Honeynut Winter Squash: Crossed variety with small fruits and resistance to powdery mildew and squash vine borers.

Learn more about how to grow summer squash, winter squash, and more varieties of summer squash in these posts. (click on the image to read the blog posts)

When to plant butternut squash:

If you live in the low desert region of Arizona, plant butternut squash seeds outdoors in mid-February or early March. This squash has a second planting window during the monsoon season in July or August. 

In other areas, planting dates can vary depending on your location and frost dates. As a general rule, you should plant seeds in the spring once the soil has warmed up and any risk of frost has passed. Butternut squash plants prefer warm weather and can grow in temperatures between 60°F to 105°F (15.5°C to 40.5°C).

How and where to plant:

To start seeds indoors, sow them in individual pots filled with good-quality potting mix. Keep the soil moist and warm (around 70°F or 21°C) until the seeds germinate. Once the seedlings have developed their true leaves, you can transplant them into your garden.

To plant seeds directly in the soil, plant them ½ to 1 inch (1-3 cm) deep. Space them 2-4 feet (.6-1.2 meters) apart if you’re planting in raised beds or containers. You can also use square-foot gardening techniques and plant one butternut squash plant per square foot if growing it vertically.

Soil should be well-drained and rich in organic matter. To improve soil fertility, add compost or aged manure.

Butternut squash plants require full sun to grow properly, so choose a location with at least 6 hours of direct sunlight daily – morning sun preferred. If you’re growing butternut squash in hot summer climates like Arizona, providing afternoon shade during the summer months prolongs the growing season.

Caring for butternut squash: 

Water plants deeply when the top couple of inches of soil feels dry. Adding a thick layer of mulch helps the soil retain moisture.

I love growing butternut squash vertically. Give them something to climb. The fruits do not require additional support as they develop. 

The vines produce male and female blossoms. If female blossoms are withering and not developing into fruit, consider hand-pollinating them. Transfer pollen from the male flower to the female blossom when the blooms are open (usually first thing in the morning). 

Tips for growing butternut squash in containers:

Butternut squash can be grown in containers, but choose a large container at least 24 inches (60 cm) deep and wide. Use good-quality potting or raised bed mix and water frequently. Use trellises or stakes to support the plants as they grow. Learn more about how to grow in containers in this blog post.

Common pest or disease issues:

Butternut squash plants are susceptible to pests and diseases, such as squash bugs, cucumber beetles, and powdery mildew. Growing vertically increases airflow and reduces powdery mildew. It also makes pests easier to spot.

If you see the leaves wilt, it’s a good sign that pests may be present. Check the undersides of all leaves several times a day and remove all stages (adult, nymph, and eggs) of squash bugs or cucumber beetles. Early detection and hand-picking are often the best methods to treat these pests successfully.  Learn more about preventing pests organically in this blog post.

Harvesting and using butternut squash:

Butternut squash takes about 80-100 days to mature, depending on the variety and growing conditions. The fruit is ready to harvest when the skin turns a deep tan color and is hard to penetrate with a fingernail. Cut the fruit from the vine using a sharp knife, leaving a few inches of stem attached. You can also harvest butternut squash when it’s still small and use it like summer squash. 

Once the skin hardens, do not leave on the plant–fruits may split.

To store butternut squash after harvest, keep them in a cool, dry place with good air circulation. Butternut squash can last for several months if stored properly. Check fruits frequently for soft spots or mold, and use or discard them right away if present.

Whether you’re a seasoned gardener or a beginner, learn how to grow butternut squash and see why it’s a popular vegetable for many dishes. 

If this post about how to grow butternut squash was helpful, please share it.