Well not all 20+ basil varieties produce the same sized plant. You'd have to be much more specific. And not all bush cuke varieties do either so the specific names of the varieties would help.

But in general I plant bush cukes in a hill/cluster of 3 plants per 3 sq. feet. Their vines easily reach 18" to 2' long.

Some types of basil can easily reach 3' tall and 3' wide but some are only small mounds no more than 8-10" square.

Dave

Dave, 3 sq ft, or 3 feet square? I don't grow bush type cukes, but 3 sq feet seems awfully small for three cukes.

A 3' square.