You don't want to grow different types of corn too close together,
right? Cross-pollination being the problem.

What about tomatoes and peppers? I seem to remember hearing something
about getting super-hot bell peppers and mild habaneros if you grow
the two too close to one another.

Can you grow, say, roma tomatoes next to grape tomatoes?

I'm trying to plan my garden layout with height considerations in
mind, and it might help things if I could put similarly-heighted
plants in the same areas, but not at the expense of having
cross-pollination screw up my yield.

Thanks for the help.

Mark