Dig a trench 5 inches wide by 7 inches deep in the area you want your raised bed placed. Fill the trench with water and allow to soak into the soil.
Fill the trench with dry concrete mix until level with the surrounding soil.
Measure a wine bottle from the bottom toward the top lip. Make a mark on the bottle at the 7-inch point.
Invert the bottle so the bottom is facing upward. Press the bottle firmly into the dry concrete up to the 7-inch mark. Push another bottle in tightly against the first bottle. Continue to push bottles into the trench until you have built an enclosed area with the bottles. Lay the level on top of the bottoms of the bottles and adjust any uneven bottles by pushing them down until all the surfaces are level.
Attach a spray nozzle to your garden hose. Adjust the spray setting to a light sprinkle. Water the dry concrete thoroughly until the concrete is damp, but not overflowing. Allow the water to absorb completely. Water the cement and bottles again about four hours later. Water twice again the following day. Once the water has soaked in, the concrete will set and hold the bottles in place.
Stack newspapers into piles approximately 6 inches thick. Lay the newspapers neatly on top of each other until all of the edges line up.
Measure across the top of the newspapers from side to side. Double that measurement. Add 20 inches to that measurement. Measure the top of the newspapers from top to bottom. Double that measurement. Add 20 inches to that measurement.
Lay the string cut for the side-to-side measurement down on a flat surface. Lay the string cut for the top to bottom measurement on top of the first string, forming a cross. Set a stack of newspapers on top of the strings. Pull each string tightly up to the top and tie in a knot to the other side. You should have a stack of newspapers wrapped with string like a present.
Stack the piles of newspapers around the perimeter of the area designated as your raised bed. For a 12-inch bed, stack another pile of newspapers on top of the first. Water thoroughly until the newspapers are soaked.
Wash the plastic milk jugs with a solution of 1 part bleach to 10 parts water. Wash the lids with the bleach solution
Fill the milk jugs with water. Replace the caps on the jugs and tighten securely.
Place a milk container with the handle side facing in toward the center of the bed in the area designated as your raised bed. Place another jug next to the first, as close together as possible. Work around the perimeter, packing the jugs tightly against each other.
For added support, turn the milk jugs around so that the handles face outward. Thread small-diameter branches through the handles, linking them to several other bottles. Overlap the branches for more support.