Q: I heard that there was an error in one of your books on the tomato spacing, what is up?

A: You are right to be a little confused.  When the All New SFG Book was published that year, we were horrified to discover that the typesetter had made some errors and the spacing that you mentioned for squash and tomatoes comes from this.  It has now been corrected in a later edition.

The spacing for vining tomatoes (indeterminate) is 1 per square foot and the plant is trained to grow up a vertical frame.  A bush tomato (determinate) needs a 3'x3' (9 square feet) space to grow and spread out.  Squash is the same spacing as a tomato except that the big winter squash that would grow up a vertical frame is planted at 1 per 2 square feet.