How do I know if my squash cross pollinated?

I have grown some glorious Hopi grey and spaghetti squash close to each other. This was probably a mistake. Is there any way to know if the seeds I have are tainted ( for lack of a better word)?

Hi Byrd, welcome to Permies!

I think the only way to know if you've created a fabulous new hybrid is to plant some and grow them out. It is completely within the realm of possibility that the new fruit could be delicious, and perhaps even be the first step to creating a new landrace variety adapted to your region and climate! Imagine a new type of spaghetti squash bursting flavor that also has inherited heirloom disease resistance from the Hopi grey.

If you want to save pure seeds from each variety, you need to bag flowers and self them (some folks even just use a clothes pin to hold the flowers closed).

If you want to be certain to try a cross, do the same and cross pollinate the two varieties.

It's also fine to let the bees do the work for you but they don't necessarily travel between male and female flowers on the same variety.

No, not without growing them out. And as each seed is unique, even if one seed from one squash is crossed, another seed from the same squash may be pure.

Depending on how long your season is, it might still be possible for you to bag and manually self pollinate and mark a female flower on each plant, and get a pure squash on each plant.

Myself, I would be tempted to save seeds from the hopi squash, and plant them out next year, and  consider it a bonus if you get any spaghetti squash crosses from the mix, as I find spaghetti squash boring tasting :)

I guess it depends on how many squash you plant. If you plant 5-10 squash each year, a few crosses are far less troublesome than if you only plant one or two per variety.

Joseph always says great parents make great offspring, and the bees are his friends!  :>)

Byrd Miller wrote:I have grown some glorious Hopi grey and spaghetti squash close to each other. This was probably a mistake. Is there any way to know if the seeds I have are tainted ( for lack of a better word)?

1) Those squash are different species. Interspecies crossing does happen, but probably isn't super likely.

2) A cross probably won't be obvious until you grow the seeds out. You can think of the seeds as individual babies and the fruit as the womb. The fruit this year will look and taste like the fruit of the mother plant it grew on. (When you see a pregnant lady, you can't ID the father by looking at her belly. She made that part alone, the father's genes didn't play a part.) I doubt you can tell by looking at the seeds, either. I think the part of the seed that's visible is genetically all from the mother. I haven't looked that up, it's possible that I'm wrong. Obviously there will be paternal genetics involved in forming the embryo inside, but you can't see it.

3) Joseph Lofthouse has made a chart comparing traits of different squash species. Go ahead and compare your seeds to it. I expect it will just show the species of the mother. When you grow out your seeds, compare the plants to it. Watch for traits of both species to show on the same plant. (Or traits mid-way between the two species. Hopi Grey is a Maxima, Spaghetti is a Pepo.)

For lots of us, interspecies crosses are a great thing. I recommend growing out any crosses you discover. But it's your garden. You can also use the chart to cull out crosses if you want to. Please know that if you find evidence of a cross, and you don't want that, you can offer your unwanted seeds for trade here. I bet someone will be interested and give you something cool for them.

I concur with the recommendations already given that the seeds are highly unlikely to have crossed, and that you can't know until next year. The two varieties are different species. The generally accepted definition of species is plants that are so far apart genetically that they can't cross. The crossing ability between pepo and maxima is especially difficult.

While I work with interspecies squash hybrids, they are extremely rare, and usually require specific techniques, and parents vetted for crossing ability.

In over a decade of closely inter-planting thousands of pepo, maxima, and moschata squash per year, I have only found one naturally occurring hybrid. The 7 seeds that the F1 hybrid produced didn't germinate.  

Occasionally, I find a natural hybrid between argyrosperma and moschata, where moschata was the pollen donor. I think of these as not quite separate species.

Great information, you guys. Thanks bunches!