An earth-filled box is a closed system growing container. Its advantages are little evaporation of the water, an even flow of moisture to the plants in the box. Other advantages are that you can grown many more plants in a smaller space. If you're an apartment dweller, you can have 4 tomato plants growing on your deck in the space of a 3 ft. area , for instance. The reservoir only needs to be filled once a week usually, I , as an example , live out in the woods, and have limited sunlight tho plenty of land. I also have deer and other lovely forest creatures, so these boxes are a big boon to me. But the yield is so great in these earth-filled boxes, that I have friends who used to have a big garden area and now grow only their potatoes and squash out there. Plus there are NO weeds, no cut worms to worry about, etc. The system is just yet another idea that is like hydroponics or the upsidedown tomato ideas.
Supplies include 2 Rubber maid or Sterlite 18-22 gallon tubs with lids, 1 pond basket, and 1 pvc tube at least 1 1/2 inch diameter and 4 inches taller than the tub you buy.