This is year 2 of the cucurbita pepo adaptation project. We are working on adapting hulless pumpkins (cucurbita pepo) to our cooler coastal climate. We chose hulless pumpkins because it can be difficult to grow crops with high levels of fat in our climate. We are excited about growing calorically dense staple crops to help create more access to nutritionally dense foods. In addition to selecting for cold-hardiness, we are also selecting for a no-till, low input system (no greenhouse, heat mats, or inputs beyond a small amount of compost). We are hoping over time to end up with a hulless pumpkin with not only tasty seeds but also tasty flesh. For this adaptation project we started last year with many different varieties of hulless pumpkins-- actually almost every type we could find online that was more resilient to the cold. The idea was to maximize diversity and to select and stabilize from there. This mix even included some hybrids that are bred for tasty flesh and tasty seeds. The initial varieties included are: Naked Bear F1 (Territorial Seeds ), Styrian (Siskiyou Seeds), Lady Godiva (Baker Creek), Kakai (Baker Creek), Pie Pita F1 (High Mowing Seeds), Emerald Naked Seeded Pumpkin (Experimental Farm Network). Lastly, there are hulless pumpkin seeds we just received that have been grown and saved on the coast. Last year we grew all of these out and saved all of the seeds. Many demonstrated hardiness for the cold and the low input system, though we have yet to find one with tasty flesh, even among the hybrids. This year I added in 2 additional seed varieties: hulless acorn from GRIN and sweetnut from Baker Creek. The hulless acorn from GRIN doesn’t seem hulless from appearance, but perhaps the hull is not very thick-- I am incorporating it anyways for the potential of the sweet flesh.
Last year it was found that seeds started earlier than June 1st had very low germination (likely still too cold and wet – they were started in flats outdoors), so this year I started the seeds on 6/6. I started half in flats and direct seeded the other half (enough for 200 square feet total). In the picture below you can see the prepared 100 square foot area for the hulless pumpkins on the right. Once the plants in the flats are ready, we will prepare an additional 100 square feet directly behind the direct seeded area and will transplant the seedlings.
Close up of the direct seeded area
6/17 some of the first hulless pumpkins are emerging
7/7 The final survivors from direct seeding in the bed emerge, including ones in my home garden which were started a bit later (maybe by 2 weeks) - I am now including the ones from my home garden (similar climate to the Inn, but better soil) since I want seeds from a larger population
7/9/25 I transplanted the squash that survived in the flats (low germ rates-- only 9 plants which is the same # as the bed-- so instead of cultivating an additional 100 square feet to plant the transplants, I plugged them into the bed with the DS squash but flagged the DS ones to continue the observations on any differences in health between DS and TPing.
7/23/25 None of the sweetnut from baker creek seeds have come up so far, and only one of the hulless acorn from GRIN, which is now ready for transplant.
7/23/25: the squash is coming along-- while the survival rate / ratio of healthy to unhealthy squash between DS and TPs is similar, it does seem that among the ones that have survived and are fairly healthy, the DS seeds are much fuller and greener than the TP ones.
On this same day, here is a photo of ones in my home garden (50 square foot area)-- more consistent but just a bit more behind due to a later planting date-- these were all DS
The climate this year in mendocino has been particularly cold-- colder than last year, with most days being very foggy and few days of sun.
8/13/25 Squash at the Inn starting to fill out a bit more with 2 extremely large and healthy plants (both DS). Those ones are so strong that they are almost crowding out/shading out the smaller squash. Hopefully there will be a large enough population to maintain genetic diversity.
8/11/25 squash at my home garden a bit more evenly happy, a bit behind the squash at the inn but still doing well and filling in.
9/3/25 at the Stanford Inn - foliage really filling out. Very robust, especially as compared to other winter squash on the property which are stunted and yellow. The direct seeded ones that survived are healthier and bigger than the transplanted ones.
9/18/25 - screenshot from a video taken; many green pumpkins growing under the foliage (at the Stanford Inn)
Reflections- while the ones in my home garden were started only 2 weeks or so later, it seems to have made a big difference in the health of the plants, especially since my home garden has fewer soil challenges and for the most part everything is healthier there (with the exception of these pumopkins)- which points me toward the only difference in their plantings which was that they were started later (the ones at home were all DS, where as the ones at the Inn were about half and half).
12/15/25: The pumpkins finished really late this year, with a few earlier, but most finishing by 12/12. There were about 20 pumpkins total from about 100 square feet collectively. We disposed of the couple that didn’t have any storage capacity and also of a couple that had hulled seeds or didn’t quite mature in time. Interestingly, both groups of pumpkins below are the same seed mix, but the ones on the left were from the Stanford Inn- much bigger, more orange, more diversity. The ones on the right are from my home garden (similar growing conditions) which are more uniform, smaller and are more green than orange. The only difference was a slightly later planting date with the ones in the home garden.
Conclusions
Next year I will plant them all a couple weeks earlier than I did this year, since the pumpkins finished really late. Even just a week earlier to try to be in the sweet spot of not being too early that they don’t germinate but not too late as to avoid slower growth and are late to finishing. All of the pumpkins I processed I kept the seeds separate so I could taste test the flesh separately as well, in case there were any sweet ones to separate out. Unfortunately that trait wasn’t existing in this batch and I think to get it, I will have to incorporate a hulled sweet fleshed pumpkin like acorn squash, but before then I am going to keep saving this current seed to get it further adapted to our growing conditions. All of the pumpkins this year from the Inn plot seemed more orange than the ones harvested last year from the initial seed mixes– perhaps more of the traits from the hybrid orange pie pita are being expressed. We ended up with 2 lbs of dried seeds from a 100 sq ft area, which is slightly less per 100 sq ft than the 6 lbs/ 200 sq ft we got last year, although last year the pumpkins had more space to expand beyond the bed borders, so it is possible that they were making use of more than just 200 sq ft. The vigor of the plants at the Stanford Inn seemed equal to or greater than the plants we were growing on our farm last year.
