While vertical farming has no official definition, it refers primarily to space efficient
plant farming. Most vertical farms are practical and economical
in producing high-value crops in a controlled environment. So-called
“greens” (leaves of plants eaten as vegetables) are predominantly grown
in these systems. In addition, virtually all vertical farms use hydroponic or
aquaponic growing systems, also called soil-less systems. Since no soil is
used, it is much more space-efficient, easier to scale vertically, and more
straightforward to design and build.