If your gonna grow in rows i'd say east to west or something like this :
. . . . . . = one plant or cluster of plants
. . . . .
. . . . . .
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spread them out a bit so they look like shrubbery etc
im just high so i decided to make a picture lol
is the barn close to your house because personally i have found alot of peoples plants growing behind their barn just becaus they live out in the boonies