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Waltham Butternut Squash Seeds

Waltham Butternut Squash Seeds

San Diego Seed Company

Regular price $6.00 CAD
Regular price Sale price $6.00 CAD
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Product Details

Product Information

Waltham Butternut Squash seeds produce uniform and delicious fruits with sweet flesh great for baking and cooking. This variety of butternut squash is by far the most popular. Known for making butternut squash soup, it has attractive, uniform, bell-like shaped features. Waltham is medium-sized with excellent flavor. Fruits can weigh up to 6 lbs (2.7kgs)! The creamy, rich, yellow-orange flesh has a nutty taste. These vines can be aggressive so plant spacing is important.

Product Details

Approx Seed Count


Seed Weight

2G, .07oz

Botanical Name

Allium cepa

Planting Season 


Soil Temp

70° F+, 21°C+

Planting Depth

1”, 2.5cm

Area to Sow

10' bed

Days to Germ.


Days to Maturity


Best Planting Method

Direct or transplant

Thin to

Final spacing

Final Spacing

≥12" apart, 30.5cm apart


30 days

Plant Spread

4", 10.1cm

Plant Height

10”-12”, 25.4-30.5cm


Planting by Zones

Zones 9-10

  • Squash should be grown in the warm season when soils are at least 70°F (21°C).

Zones 2-8

  • Direct seed in the spring once soils have warmed.

Planting Waltham Butternut Squash Seeds

  • In Zones 9 and 10, you can direct seed or transplant out your squash. We recommend direct seeding into freshly irrigated soils.
  • To direct sow, plant seeds in debris-free, well-worked soil that has been deeply watered. Cover with 1″ (2.5cm) of finely sifted soil.
  • If you are planting seeds in starter pots, plant seeds into thoroughly moist high-quality seed starting soil. Place seeds on top of the soil and cover with 1″ (2.5cm) of finely sifted soil.
  • Once your squash has germinated and the first set of true leaves show, fertilize with an organic liquid fertilizer. When the plants are 3-4″ (7.6-10.1cm) tall you can plant them out into the garden. Space at least 12″ (30.5cm) apart.

Growing Waltham Butternut Squash

  • Squash should be planted into deeply irrigated, fertile soil. In Zones 9 and 10, adding tons of compost will help create a healthy soil structure and keep soil moistures in.
  • Mulching heavily around your plants will also help with weed suppression and moisture retention.
  • Pollination is key to producing squash. You should hand pollinate your squash if you doubt you have good pollination.
  • More information about growing butternut squash is on our blog!

Harvesting Waltham Butternut Squash

  • Squash are best harvested at peak ripeness. There are two ways to know that your fruit is ready, this is by knowing what kind of squash you are growing.
  • Summer Squash is eaten when it is young and tender. You want to be able to pierce the flesh of the squash with your nail.  These are crops like zucchini and scallop squashes among others.
  • Winter Squash is a squash that will mature with a hard outside and can keep for several months through the winter. Hence the name! These squash you want to fully mature on the vine.
  • Learn when to harvest butternut squash in our guide.

Growing Squash in Containers

  • Squash plants like to grow across the ground but alternatively can be grown up a trellis if hanging fruit are supported. If growing in a container, make sure your container is at least 20″ (50.8cm) deep. Keep in mind containers will dry out faster because they have more surface area and less soil to hold onto moisture. Mulch heavily on the top layer of soil in the pot to keep the soil from drying out or heating up too much.

Southern California Pro Tips

  • Mulch heavily around your squash plants to ensure the soil does not dry out or overheat.
  • Do not overhead water as this promotes foliar diseases.
  • Grow at least two squash plants to ensure good pollination.

Companion Flowers/Crops

  • Squash are aggressively growing plants that look wonderful with cosmoszinnias, and sunflowers.

Additional Learning Resources

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