I grow my summer squash plants about 2 ft apart in rows. This is crowded but usually some plants die off later as to thin them out. Not certain what you mean by "mix" as my 4 varieties are all mixed without harm. If you are growing heirlooms and want to save seed then those plants should be isolated as much as possible.

Thanks, VGKG
My Rouge De Vif DeTempes (not sure of spelling)are yellow rather than orange.
I think they cross-polinated with lemon squash or cushaw.
What I want to know is how far to separate them next year.
Thanks again,
Charlie

If you are planning to save seed then precise planting distances is somethig that I'm unsure of. Best to separate the seed saved variety as far as away you can plant it. No squash should change it color or appearance if it's growing close to other squashes, only in the next generation of seed would new characterists show up from cross pollination.