I must be extremely obtuse then. Because I foliar feed everything in my garden and my foliar fed plants almost always out produce my non-sprayed plants. Plants collect nutrients via wind blown detritus, animal/bug droppings, leached compounds brought down out of the canopy via rain... many ways. It is a proven fact that plants can absorb nutrients via their epidermis and stoma. Foliar feeding is a especially effective to provide your plants with trace nutes that are hard to balance in soil/hydro. Hormones in kelp extracts, a popular foliar feed, have been shown to promote cellular development, helps prevent pests and helps prevent fungus and molds.