Corn will grow well with squashes, peas, beans, but don't plant onions or garlic near peas or beans. For corn make sure the roots never show on top, it is disastrous, grow them in a small ditch 6 inches deep row, plant the seed in the row, and as the corn grows to 3 1/2 feet tall, fill it in 8 inches , 2 inches over the normal 6 inch height of your ditch. Use lots of fertilizer with it.

Don't plant tomatoes next to corn, I've read opposite, but half and half of the sites you find say not to grow them next to each other.

Collards are cool weather crop and mine did better in the fall. Maybe plant them under something bushy and tall to shade them. Some grow the tall, I pick them at 3 to 6 inches, so if you pick them small, you can have more above ground space and they will fit nicely under something.

The sun rises east to west, plant all your tall stuff North, short stuff south.

Have you considered raised beds or square foot gardening? That may solve your good neighbor/bad neighbor plant issues. There is a really great book on the topic by Mel Bartholomew.

Kim

Suggestion: Install a six-foot-heigh trellis on the North end for growing peas, beans, melons, cucumbers, and other climbers.

T-bars/stakes make good, sturdy poles, and re-bars attached to top of t-bars/stakes are also good, but black/gas pipes are better (and more expensive) top poles. For netting, get the kind that has big openings, so your hands easily fit through (see link). Electric straps are good for attaching net to side and top of stakes/poles.

Here is a link that might be useful: Hortonova net fr trellis

I read that stuff about planting corn next to tomatoes too. Most sites say not to plant them next to each other, because the same worm attacks both. But, if I remember correctly, another site suggested planting them next to each other, using the corn as a trap crop, to keep the worms away from the tomatoes. But none of them ever tell you how close is too close. Or for example, if 100 square feet of tomatoes next to 100 square feet of corn will attract more worms than 200 square feet of just tomatoes. I ended up separating them with one 4 foot bed, and have no idea if it made any difference. This year, I'll probably do the same thing. But I have a feeling the 32 x 45 foot garden they're going in may be too small for the spacing to make much difference.

Make sure you don't make your beds too wide or you won't be able to reach the middle! 3 to 4 feet wide is good, depending on your height. You may want to draw an imaginary line on the ground you can't cross and see how far past it you can comfortably reach without having to worry about squashing your imaginary plants to get to the middle!