I have a 3' x 5' raised bed (this is a guesstimate; I haven't taken measurements with the box yet to figure out the exact size) and I plan to use the square foot gardening method.

Can I still divide the box into the sixteen 1' x 1' squares you normally divided a 4' x 4' box into?

Also I was planning on growing 64 bean plants in the squares (4 bean plants per square x 16 squares=64 plants)

For the size of the box I'm using will this be too many plants?

I also would like to grow zucchini in a 4' x 4' bed, and would be using the square foot method too and again would be dividing the 4' x 4' box into 16 squares.

I read something where if you do vertical gardening you could grow 1 zucchini plant per 1' x 1' square; if I were to do this could I do 6 plants in a 4' x 4' box? If this is feasible, I'd have 10 squares leftover and was wondering if I could grow pepper plants in the remaining 10 squares or would that be overcrowding the box since I'd already have zucchini in it?