Knowing the growth stages of butternut squash is key to successful cultivation. In this guide, I share personal experiences and insights to help you recognize each stage, avoiding surprises or confusion.

I'm not the best at labeling my plants once they go into the field.

Those little markers always get lost in the mulch, or picked off by one of my dogs. I'll find them scattered by the wrong plants, or they'll simply vanish into thin air.

So imagine my surprise when I saw that I was growing a striped squash! I couldn't remember planting any striped squash variety besides Delicata, and these did not look quite the same.

These mystery cucurbits were more curvy, like a butternut.

Maybe I got some seeds that cross-bred? I decided to leave the "mutant" squash to grow just to see what would happen.

Overtime, those green stripes faded away to reveal the creamy golden tones of butternut squash!

Who would have thought?

In this guide, I'll show you the different butternut squash growing stages so that you can recognize what it looks like when it's ripening...so you won't be confused like I was, or even worse, throw your plant away!

Butternut Squash Stages of Growth

Stage 1: Seedling Phase:

Seedling Care & What to Expect

The seedling phase begins when the seeds sprout, which typically occurs 7-14 days after planting in warm, moist soil.

During this stage, butternut squash plants focus on root development and establishing sturdy seedling leaves.

It's crucial to maintain consistent moisture and protect the seedlings from harsh winds and pests. I've learned to use temporary covers or netting to keep curious dogs and other critters at bay.

How long does it take for butternut squash to grow from seed to harvest?

Butternut squash typically takes between 85 to 110 days to mature from the time of planting. This timeline can vary slightly depending on environmental conditions and care practices.

Stage 2: Vegetative Growth:

Key Growth Markers and Care Tips

‍The vegetative stage is marked by rapid vine growth and the emergence of large, lobed leaves. Ensure your squash has ample sunlight and space to spread.

This stage requires regular watering and the application of a balanced organic fertilizer to support vigorous growth.

My go-to fertilizer of choice for winter squash at this stage is feather meal, since it's high in nitrogen.

What can I do if my butternut squash plants are wilting?

Wilting can be caused by various factors, including pests, diseases, or water stress. Ensure the plants are adequately watered, and inspect the vines for signs of squash vine borers or other pests. Remove any infected plants to prevent the spread of disease.

Stage 3: Flowering and Pollination:

How to Support Pollination

Flowering occurs 40-50 days after planting. Butternut squash produces both male and female flowers, which rely on pollinators like bees for fruit set.

To enhance pollination, I plant companion flowers such as nasturtium, marigolds or calendula nearby.

During this time, I'll fertilize my squash bi-weekly with a mix of organic fish bone meal (for some nitrogen and phosphorus), organic kelp meal(for potassium), and OMRI-certified cottonseed meal (for phosphorus and potassium).

How can I tell the difference between male and female squash flowers?

Male flowers usually appear first and have a straight, thin stem. Female flowers will have a small, bulbous fruit at their base, which is the ovary, and this is what develops into the squash once pollinated.

Stage 4: Fruit Development:

Monitoring and Supporting Fruit Growth

‍Once pollination is successful, you’ll notice small fruits beginning to swell.

Monitor the development closely, ensuring the vines have enough support to prevent fruit damage.

Consistent watering and mulching help maintain soil moisture and protect growing squash from soil-borne pathogens.

Why aren't my butternut squash fruits developing even after flowering?

This issue is often due to inadequate pollination. Butternut squash plants produce both male and female flowers, and fruit development requires successful pollination, typically by bees. Planting companion flowers like marigolds can help attract pollinators.

Stage 5: Ripening:

Signs of Ripeness and Harvest Tips

‍Ripening typically occurs 85-110 days after planting.

Butternut squash is ripe when the skin turns deep tan and cannot be punctured with a fingernail.

Signs of readiness include a hardened stem and a uniform tan color without green streaks.

Stage 6: Harvest-Ready:

Harvest + Curing Guide:

When butternut squash is fully mature, cut the fruit from the vine, leaving a couple of inches of stem attached to prevent rot.

Store in a warm, dry place to cure for 10-14 days before winter storage.

What are the signs that butternut squash is ready to harvest?

A ripe butternut squash will have a deep tan color with a tough skin that you cannot puncture with your fingernail. The stem should also be hardened and the squash should be free of green streaks.

Butternut Squash - One Seed Turns Into Huge Harvest

When growing butternut squash, I feel like each stage of growth is a rewarding part of the summer season.

From the first tender seedlings pushing through the soil to the robust vines laden with future harvests, butternut squash offers a bit of delight as it reaches each milestone in its lifecycle.

When you nuture your plants and understand their needs at every phase, you not only cultivate a bountiful crop but also deepen your connection to the rhythms of nature.

Whether you're savoring the fruits of your labor in a hearty soup or sharing them with family and friends, the satisfaction of home-grown produce is such a good feeling to experience.

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Learn more about the different kinds of winter squash in my in-depth squash variety guide here.

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