Winter Squash Seeds,
Burpee's Butterbush Butternut

This squash should be planted after the danger of frost has passed, as it is highly frost-sensitive. Ideally, sow the seeds or transplant seedlings when the soil temperature consistently stays above 65-70 F. In most regions, this means planting in late spring to early summer. If starting seeds indoors, do so about 4-6 weeks before the last expected frost​. If you’re not sure how to find your first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

Direct sowing is recommended once the soil is warm. Plant seeds about ½ to 1 inch deep and space them 18-36 inches apart in rows that are 3 feet apart. If space is limited, consider planting on small hills or mounds, which can improve drainage. For bush varieties like Burpee’s Butterbush, planting in hills with 2-3 plants per hill can also optimize space​.

Burpee’s Butterbush requires consistent moisture, especially during dry spells. Avoid wetting the leaves to prevent fungal diseases. A balanced fertilizer, rich in nitrogen during the early growth stages and higher in phosphorus and potassium as the plants mature, will support healthy growth and fruiting.

• There are four different species of squash: Cucurbita maxima, C. pepo, C. moschata, and C. mixta. They will not cross pollinate with each other, so it is possible to grow one of each species for seed saving without worrying about cross pollination.
• If you are planning to grow several varieties of more than one species, you can bag the blossoms and hand pollinate to avoid crossing.
• Whether it is a summer or winter squash, you must let the fruit completely mature before extracting the seeds, and cure for at least two weeks.
• Scoop the seeds, place them in a bucket, and add just enough water to cover. Let sit at room temperature to ferment for two days before rinsing off the pulp.
• Lay seeds out to dry on newspaper or paper plates.
• Stored in a cool, dry place, seeds will remain viable for up to four years.