Tools and Materials
How Does Butternut Squash Grow?
Butternut squash plants are sensitive to cold, frost and chilly soil. The seeds only germinate in warm soil and the seedlings require consistent sunlight. The vines grow quickly but the fruits have a long growing season of about three to four months from the time of planting.
Growing Butternut Squash From Seeds
Butternut squash can be grown both indoors and outdoors. Direct seeding in the garden is preferred, but indoor cultivation is helpful if you live in a region with short summers.
Growing Butternut Squash Indoors
To successfully grow butternut squash indoors, start the seeds approximately four to six weeks before the last frost date.
How to Grow Butternut Squash Indoors
Step 1: Add Soil to Pots
Begin with enough sterile, moist soil to fill two 3- to 4-inch biodegradable garden pots.
Step 2: Plant Seeds
Plant two seeds in each pot, 1-inch deep. Place the pots near a sunny window. Keep the soil moist and warm.
Step 3: Check for Seed Germination
If both seeds in a pot germinate, note the strongest one and snip the other with scissors at the soil surface. Don’t pull; pulling can damage the root system of the remaining plant.
Step 4: Upon Sprouting
Once a plant has sprouted, provide 12-14 hours of strong, full-spectrum light daily.
Step 5: The Second Set of Leaves
As the seedlings sprout their second set of leaves, place the pots outside in the partial sun for a few hours daily. Bring the plants inside again at night. Slowly increase the number of hours they spend out in the sun. This will help them acclimatize to the outdoor environment.
Step 6: Plant the Seedlings
Once the outside temperature reaches 65 degrees Fahrenheit, plant the seedlings in the ground.
How to Grow Butternut Squash Outdoors
Step 1: Space Out Your Rows
Space your rows so that they’re about 6 to 8 feet apart to allow for long vines.
Step 2: Prep the Soil
Use a shovel to loosen the soil in the area you want to sow the seeds. Prep the soil with compost or organic matter.
Step 3: Form Mounds
Gather the soil in the center of the area to form a mound, each about 6 to 12 inches high.
Step 4: Plant the Seeds
Plant three to four seeds about 36 to 48 inches apart. Regularly water the seeds and ensure the soil is always moist.
Caring For Butternut Squash
A butternut squash vine can yield a significant number of squash by following the care instructions below.
Soil
The plant needs well-drained soil with plenty of organic matter. During the growing season, add organic compost or composted manure to the top layer of soil to provide the necessary nutrients.
Fertilizer
Fertilize the plant with compost tea or liquid fertilizer every two to three weeks. Butternut squash is a heavy feeder and needs supplemental nutrients during the growing season.
Always wear chemical-resistant gloves and safety goggles when applying liquid fertilizer. Read and follow the instructions on the fertilizer label.
Sunlight
Butternut squash needs full sun at least 6 hours a day. If growing indoors, keep the plants near a sunny window. In summer, it’s normal for the plants to overheat and wilt during the day, only to revive when the sun goes down.
Temperature
Butternuts are susceptible to cold and will only germinate in warm soil. For proper germination, the soil temperature should be between 65 and 70 degrees Fahrenheit.
Water
As the plant grows, it will require more water each week. Butternut squash plants need at least one inch of water every week. Seedlings must always be kept moist but not soggy. If the plant leaves are wilted in the morning, water them immediately and try giving the plants some afternoon shade.
Common Pests and Problems
Butternut squash is vulnerable to aphids, beetles, powdery mildew and squash bugs. You can plant resistant squash varieties (such as royal acorn and sweet cheese) nearby to combat the pests. If the infestation is too severe, remove the infected plants to prevent the spread to other healthy plants. This is true for other butternut squash plants that may mildew or disease as well.
Beetles can be removed by hand and placed in a bucket of soapy water. Additionally, proper spacing and thinning of the plants helps reduce the spread of disease and improves airflow, minimizing moisture that can lead to disease.
How to Harvest Butternut Squash
Butternut squash should be harvested when the color is dull gold with no green streaks, typically late fall to early winter. Gently press a fingernail to the fruit's skin. If there’s no mark, the squash is ready to be harvested.
Cut the fruit from the vine with a garden knife. Cure it in a dark, warm room for one to two weeks before storing.
Growing and Caring for Butternut Squash
As you set yourself up for a strong harvest, remember the essentials:
- Plant in well-drained soil enriched with compost.
- Give vines plenty of space to spread.
- Provide seedlings at least 12 hours of full sun daily.
- Water consistently and feed regularly during the growing season.
- Watch out for pests that can damage plants.
- When the rind turns dull gold, your squash is ready to pick and cure.
Ready to start? With a little work and the right materials, you’ll soon be harvesting your beautiful crop of butternut squash. Shop online at Lowe’s and find everything you need, from seeds to biodegradable garden pots, we have you covered.
Butternut Squash FAQ
Frequently asked questions that may help you when it’s time to grow and care for tender winter butternut squash.
1. When is the Best Time to Plant Butternut Squash?
Plant butternut squash after the last frost, when soil temperatures consistently stay above 65 degrees Fahrenheit.
2. How Long Does it Take for Butternut Squash to Grow From Seed?
It typically takes 90 to 120 days (3–4 months) from planting to harvest.
3. How Often Should I Water Butternut Squash?
Water deeply once or twice a week, providing about 1 inch of water weekly. Keep soil moist but not soggy.
4. Do Butternut Squash Plants Need Full Sun?
Yes, they need at least 6 hours of direct sunlight per day for healthy growth and fruit production.
5. What Kind of Fertilizer Works Best?
Use a balanced fertilizer or compost tea every 2–3 weeks during the growing season.