Plz don't suggest looking up something on companion gardening. This isn't really what I'm doing, it's just the best terminology I can think of for it.

The main reasons for doing this are to maximize a very limited amount of gardening space, and to extend the harvest because of having a short growing season.

The ideas I have are listed below, but they're purely speculation. I don't know if they'll work.

Corn with melons and/or squash (this IS NOT three sisters)

beans with leafy green stuff (to shade the greens)

fruiting crops (tomatoes, eggplant, peppers) with root veggies. I figured this would be a natural since they'd shade the root veggies, and since both need potassium and phosphorus. However would this cause them to compete for food?

I'm also wondering what tall crops to pair with brassicas (cabbage, broccoli, cauliflower, kohlrabi, turnips). I heard these are tricky to find other veggies that pair well with them.

Also kohlrabi and turnip are brassicas, but they're also root veggies. So should they be paired with fruiting crops mentioned above, or with whatever veggies you'd pair brassicas with?

I think the corn would shade the melons too much. Also, without the 3rd sister, you would need to fertilize really good.

Beans are commonly planted with corn, cucumbers, savory, carrots and celery. They HATE onions.

From what I have read interplanting the kohlrabi and the turnips would be fine, because they use different soil stratas and they take the same kinds of culture and nourishment.

Tomatoes like basil, marigolds, nasturtiums, onions, garlic. They benefit from carrots, but carrots get a little stunted from the tomatoes. Tomatoes do not like brassica family members or potatoes and fennel.

Cauliflower should not be planted by tomatoes or strawberries.

I hope that helps. You will also have to remember about crop rotation. when you start with companion planting, it can make crop rotations harder to do.