Squash, corn, varieties, oh my!

Hey yall, trying to get the plan started for the garden next year and be as prepared as possible. I want to keep as much seed as possible and be having seed that can become generations of plants that are used to my garden, my climate, etc. Some things I would like to keep as it's own variety and I'm curious if I need more information on placement.

Ohio. Last frost est May 5. First frost est Oct 8. Est 155 days.
Planning to get silage tarp to solarize and help prep garden. 24ft x 105ft. Hopefully will be two areas that size, separated by a few hundred feet.

-Lemon squash, mixta, summer.
-Connecticut field pumpkin, pepo, 100 days, ~20#
-New England sugar pie pumpkin, pepo, 100 days, 4-5#
-Acorn squash, pepo, 80 days, 1-2#
-Butternut rogosa violina gioia squash, moschata, 100 days
-Georgia candy roaster, maxima, ~10#
-Jarrahdale squash, maxima, 100 days, ~6-10#, blue!
-Nanticoke squash, maxima

I'm still sorting out which family can or can't cross, or extremely unlikely to anyhow. The lemon squash could put in large containers if needed to grow them well away from the rest. They are very small lemon sized summer squash and I'm sure would be very wacky crossed with anything of the rest! If anyone has approximate weights or days to harvest for the ones I didn't list I'd be interested to have an idea to go off of, weren't listed on the seed sites.
I know for sure that I like butternut and wanted to grow those to themselves for 'pure' variety seed. Same for the Acorn.
The field and pie pumpkins I'm not too concerned about, I can just keep seed from them and end up with pumpkins of various sizes. I can grow excess of these because they make terrific feed to flush the sheep preparing for breeding.
Georgia roasters I'm not sure how they will fare, I got interested in them via a friend but I think they are quite long season. I think she grew them like three years, one with no ripened fruits, one with half fruits ripened, and one year they did great. So I'm guessing a more southern variety, as per the namesake state. So I'd like to do these themselves just to make sure they don't cross into the others.
The Jarrahdale I got purely because they are soooo pretty! And as I said, I won't be overrun really with pumpkins. I would definitely be interested to try crossing this to see what happens but I'd love to have some that are 'pure' variety.
The Nanticoke I got because I binge read all of Joseph Lofthouse's posts and listened to the podcasts with him and Paul. So I ordered seed from Experimental farm network.. And if I'm going to order then order everything!!! So now I'm hooked on landraces...

With so many varieties and seed I was thinking to plan for maybe 5 plants of each? That way it won't be The End if one or two die off etc, and I won't need to plan whole plots of each type. Next year I'm hoping to optimize trying lots of things and in the future I can par down as needed for what does well or what I like.

I have alot of different things to go in the garden. As I've seen in other threads, the farther apart the varieties are, the safer from cross pollinating. And when there is alot of plants like the garden the bees will go along your squash a while, then along the beans for a while, then the tomatoes a while,... So if there is many things between the varieties of squash then you should also be safer from cross pollinating. Did I understand that correctly?
So for my 105ft garden am I better off to do say either far end with a variety? If I put another variety in the middle am I asking for cross pollination?

I also have several varieties and landraces of corn I'd like to try. Again, I'm happy to do smaller stands of them to test how they do here before paring down to what I want. I was thinking sweet corn in one garden section and the high carotene corn in the second garden section a few hundred feet away. Then if possible find places a few hundred feet away for a small plot of only the flour corn, and another for only the grain corn. If not I can pick two to do next year and the other two the following year. How far is fairly safe for corn varieties?
I am really excited about the flour corn because my dad is the miller of the local historical society. He's in charge of the antique flour mill equipment. So I can very easily have grain custom milled and could setup to use the working antique seed cleaner.
-Dorinny sweet corn, 75 days, 4-5ft tall
-Lofthouse flour corn
-Lofthouse high carotene flint corn
-Harmony grain corn

I grew Nanticoke squash last year, it's quite an easy way to get into landrace gardening - very diverse colors and shapes in there.
Quite a bit of variation in taste as well.
Here's what I got from those plants



If you really want to keep things from cross-breeding, then yes, more distance and a barrier of sorts would definitely help.
I think the lemon summer squash is actually a pepo and not mixta, so if possible keep it well away from other pepos.

With the corn, you might consider growing the different varieties next to each other.  As long as they don't tassel at the same time, they won't cross.

If the time to harvest is 2 weeks apart, tasseling may not overlap. Maybe sow one variety as soon as possible,  and wait 2 weeks to sow the next variety.

Your plan for the barriers and distance between squash sounds good to me. You can always rogue out an occasional cross, if needed. I'd be nervous with only five plants of each for pollinating, but my bees might be kinda dumb.

I grew Nanticoke either last year or the year before and didn't like them much. I found they were quite watery compared to the maxima mix I usually grow. It's got kabocha, buttercup, galeux d'eysines, hubbard, and probably some other ancestors. And I didn't like the flavour of a few of the Nanticokes AT ALL. There was one that tasted very strongly of cucumber. That in itself might not have been bad, but the mealy texture made it pretty gaggy.

In more than a decade of growing thousands of squash per year, of all species, all jumbled up, I have only noticed one naturally occurring hybrid involving pepo/maxima/moschata. And the seeds didn't germinate, so it was lost.

I consider mixta and moschata to not quite be separate species. I observe occasional crossing between them, with moschata donating pollen to mixta.

The pepo are difficult. Acorn and Connecticut field pumpkin are different sub-species. Crosses between them are troublesome for me. Too hard to work with. For that reason, I only grow one sub-species or the other, but not both. For example, I grow Acorn and Delicata squash together, because crosses between them are still nice small winter squash that taste great.

I grow all maxima squash together, without regard for variety names or crossing. Then select for fruits that weigh from 3 to 10 pounds. and taste great. I don't care about shape of skin coloration.

I treat the moschata squash the same way, selecting for fruits from 5 to 15 pounds. I generally prefer long-necked for ease of use in the kitchen, but keep a few round squash seeds for the sake of genetic diversity.

In every squash species, I select for dark yellow/orange, for the sake of improved flavor and nutrition.

In a ten mph wind (the average at my garden) corn pollen falls below silk level by 25 feet.

I see around 5% cross pollination rate on squash planted 100 feet apart.

Thanks all! Baker creek is where I got the lemon squash seed from, they list it as mixta. A quick search turned it up on another site listed as cucurbita pepo. So I will err on the cautious side and see if I can plant them quite away from the others.

I saw acorns were pepo turbinata, after the wiki rabbithole reading up on the different family branches of squash. Good to know.

So as a rule the family names won't cross, just within the same family name. ...with the rare moschata being a pollen dad to mixta. Got it!

I still need to look at space needs for everything. I'm thinking if I plant the squashes at the far ends and run the vines out then I can optimize ground space for the rest of the plants.