Ideally, hives are spaced at fairly wide intervals to help avoid drifting and disease transmission. Unfortunantly, for the vast majority of us, that is simply not practical. Space your hives as you see fit to work into your landscape. One thing most of us do is leave enough room behind the hive to work it from the rear. I place my hives on a stand made of 4x4x8's and get 5 10-frame hives per stand. They are almost touching each other. The stands are about 5 feet apart so I can get the mower through and are arranged in a square with the entrances facing inwards. Everyone has their own way and they all seem to work.