Hulless Zucchini

[A Horn]

I am crossing Kakai hulless pumpkins with Costata Romanesco to hopefully create a zucchini with seeds that are unobtrusive even when the fruit is over developed.

I successfully crossed them both ways this summer and I will grow the f1 out next year

[Garrett Schantz]

These fruits look like a mix of Kakai Hulless and Costata Romanesco.


The long fruits don't have the correct coloration for Costata Romanesco.

And I don't believe that Kakai Hulless Squash gets those shapes.



If those are the results from crossing Kakai and Costata Romanesco, those would be the F1.

The first results of crossing two plants / varieties together.


So, whatever you save from that initial cross is then an F2.


I've heard that Kakai isn't very borer or pest resistant, and that it's susceptible to powdery mildew.


Emerald Naked Seeded, is powdery mildew and black rot resistant.

It's the result of crossing a disease resistant pumpkin, and a bunch of hulless squash.

It probably has a higher seed to flesh ratio than Kakai.



I've read that storing hulless seed, they sometimes have rot or mold issues.



Nice project.

[A Horn]

These fruits look like a mix of Kakai Hulless and Costata Romanesco .

The long ones are poorly pollinated Costata Romanesco. (I kept waiting for bees to show up, but they never did) the short one is Kakai hulless pumpkin. Both from Quail seeds

I've heard that Kakai isn't very borer or pest resistant, and that it's susceptible to powdery mildew.


Emerald Naked Seeded, is powdery mildew and black rot resistant .

Thanks for the advice, I might do the cross again with emerald naked seeded and a different zucchini

I've read that storing hulless seed, they sometimes have rot or mold issues.

I also had very poor germination so I think it doesn't store very long even without damage

[Klaus Brugger]

Cool project!

Years ago, I grew 'Arenborner Walze' bred by the late Ludwig Watschong in Germany. It has hulless seeds, a bush growth habit and elongated fruits. The fruits are more marrow-shaped though and not like really long-fruited zucchini or cocozelle. The old Austrian 'Tschermak-Kürbis' is similar. I'm sure your new cultivar would be a novelty.

I quite liked 'Arenborner Walze', but I guess by the time lignified seed coats would have become an issue, I wouldn't have wanted to eat the whole fruit anymore, anyway. Do you find that over-developed 'Costata Romanesco' fruits are good to eat as a whole apart from the seeds? Are you planning to add some other genetics to the mix?

Pictures of 'Arenborner Walze'
Left: Immature fruits of different developmental stages
Right: Physiologically mature fruits with fully developed, "hulless" seeds

[A Horn]

Three of last year's five fruits hybridized successfully and the nine plants that I planted are growing medium-sized (but larger than both parents) oblong squashes. They didn't inherit the ridges from costata romenesco.
They also have an interesting range of variation in surface pattern.