When I teach intro classes on permaculture design, when we're talking about boundary optimization -- that is, when to maximize the edge and when to minimize it -- one of the questions I like to ask students is along the lines of, "How many strawberry plants, spaced 6" apart, can you fit in 16 square feet and still reach them all easily for harvest?" The exact numbers are not important; what I'm looking for is the ideal design of a strawberry planter to maximize production in a minimum of space.