A plant growth system and medium employs a manmade mineral fiber-based growth medium that includes from about 40% to about 99.5% man-made mineral fiber interspersed with from about 0.5% to about 60% by weight pieces of natural or synthetic open cell foam. The foam includes from about 5 to about 50 pores per square inch. Additives in the form of nutrients, fungi, and bacteria are included. Water is supplied to plants by flood and drain watering during plant growth in the medium. EC is maintained within a range of about 0.5 mS/cm to about 2.500 mS/cm and pH is maintained within a range of about 5.6 to about 5.8.
