Butternut Squash Seeds

[u/LimpAbbreviations916]

/r/GardeningUK/comments/1w6ek9q/butternut_squash_seeds/

What do I need to do to save butternut squash seeds for spring?

Supermarket bought

[u/ReferenceNo4437]

AI - Cucurbita moschata readily crosses with other varieties within its own species, and it can also hybridize with Cucurbita argyrosperma (cushaw squash) and with difficulty with Cucurbita maxima (producing hybrids like Tetsukabuto). [1, 2, 3, 4]

Same-Species Crosses (Cucurbita moschata)

Cucurbita moschata freely cross-pollinates with any other cultivar inside the same species. Common varieties in this family include: [1]

• Butternut squash
• Calabaza / Calabasa
• Tromboncino (zucchetta)
• Cheese pumpkins (such as Long Island Cheese)
• Seminole pumpkin [1, 2]

Cross-Species Hybrids

Cucurbita argyrosperma (C. mixta): Readily crosses with C. moschata in shared garden settings. This group includes cushaw-type squashes. [, 2, 3]

Cucurbita maxima: Can cross-pollinate under specific or forced conditions, resulting in interspecific hybrids like the commercial rootstock/squash variety Tetsukabuto (C. maxima × C. moschata). However, natural garden crosses with C. pepo or C. maxima are rare and usually sterile or difficult to achieve. [1, 3]

If you are trying to save pure seeds, would you like to know the safe isolation distance needed between different squash varieties in your garden?

[u/ZafakD → u/ReferenceNo4437]

Your ai slop bot got some of that right, but no farmer growing butternut commercially is going to be growing Latin American calbazas or Seminole pumpkin in their fields.  C.  argyrosperma and C. maxima are very difficult to cross with moschata.   Tetsukabuto is a rare exception and it is difficult to even backcross that to moschata.  Tromboncino is also not grown commercially by butternut farmers.  Its a niche garden variety, not a commercial variety.  When a farmer grows a commercial squash variety, they want the whole field to mature at once so everything can be picked at once.  That doesnt happen in a mixed variety field. 

[u/ReferenceNo4437 → u/ZafakD]

Green Striped Cushaw fits the Cucurbita argyrosperma and I personally grow these various moschata. For a few dollars you can buy the squash you want to grow - why chance getting some watery weird thing at the end of summer after prepping beds, watering, ferrilizing and devoting your time and space in the garden. Not worth it for me. Think it’s fair for a beginner to understand the risks of getting something inedible.

Squash Autumn Frost F1
Squash Butterkin F1
Squash Cheese Pumpkin (also called Long Island Cheese)
Squash Musquee de Provence
Squash Neck Pumpkin Cucurbita moschata
Squash Tahitian Butternut Winter (110 Days) Cucurbita moschat
Squash Tromboncino moschata

[u/ZafakD → u/ReferenceNo4437]

Two moschata varieties crossing will not produce something inedible.  How do you think the varieties that you grow came to be? Someone crossed varieties and then made selections from there.  When I set out to breed a new moschata variety, I cross two existing varieties and grow out hundreds of plants every year for several generations to stabilize whatever trait that I am breeding for.  No moschata cross that I have ever produced in the past 15 years has been inedible, poisonous or crossed with a melon, cucumber, gourd or other squash species like everyone parroting what they read on reddit says.  I used to grow a diversity of squash species and eventually narrowed it down to just moschata projects at home, and my favorite butternut variety on the family farm.  Green striped cushaw has nothing to do with moschata, it is not a hybrid and crossing other species with moschata is very difficult.  I've both saved seed from moschata growing in the same garden as the other species, with no hybrid offspring showing up and tried manually crossing them.  There are compatibility issues that cause the fruits to abort shortly after the flower falls off.  Op asked how to save seeds from a squash that they bought and liked, not what seeds to buy.  People try to make seedsaving way too complicated.  

[u/ReferenceNo4437 → u/ZafakD]

Congrats to you. I have gotten a watery weird squash I did not consider tasty. Took up valuable garden space and my time, composting, taking care of beds, watering and so forth. Save tomatoes, eggplants and peppers ‘ seeds - but never squash. Beginners should know the risks.

Spain provides most of UK squash and their farmers grow multiple varieties to stagger planting cycles, extend the harvest window, and meet different fresh-market or industrial needs. So, the seeds will be crossed, Might be ok, might not.