An earth box is a way for apartment dwellers with a limited growing space to plant a small garden indoors. In an earth box, a reservoir for water is separated from the soil. A porous container of earth acts as a wick, drawing water from the reservoir into the soil. There are numerous variations of the same basic design. Four high-yielding tomato plants can be grown in one of these clever containers.
Mark a line around the outside of the lidless plastic tub to match the height of your pond basket (5 inches from the bottom of the tub). Following this line, use the saw to cut the tub in half. The bottom portion will be the base of your earth box; you won't use the upper portion.
Put the pond basket upside down in the center of the upturned base. Using the basket as a template, trace around the top of the pond basket. Remove the basket. Cut a hole that is 1/2 inch smaller than the shape you have traced.
Drill a 1-1/2-inch hole in the bottom of the base at one corner, and then drill about 40 evenly spaced, 1/4-inch holes around the bottom.
Put the pond basket upright in the bottom of the second tub. Slip the base you cut from the first tub inside this intact tub, resting it on top of the pond basket.
Drill a 1/4-inch drainage hole near the top of the base through both the outer tub and the inner base. The inner base will be your planting tray, and the space between the inner base and the bottom of the outer tub will be your water reservoir. The drainage hole is simply to warn you that you have added too much water. You'll quickly learn when to add water and how much. You shouldn't have to buy a tray to put under your earth box.
Drill a 1-1/2-inch hole in the corner of the rim to match the hole in the base. The hole will support your water tube.
Cut out the center of the top lid, leaving about a 2-inch rim. If necessary, leave more rim near the corner with the 1-1/2-inch hole so that you do not ruin the support for the water tube. Discard the plastic cut from the center of the lid.
Cut the PVC tubing so that it is 4 inches taller than the intact tub. Thread the flexible tubing through the matching holes in the rim and base.
Add soil to the top tub, add water through the PVC tubing into the outer tub, and plant your seeds. The roots of the plant draw water up through the pond basket. The holes in the base allow excess water to drain back into the reservoir.