Compost is a rich organic matter that improves the quality of soil, which ultimately affects plant health and growth. Although this nutrient-dense matter is easily available in nurseries and garden supply centers, it can be made at home with kitchen and garden scrap. Red worms or red wrigglers play an important role in the process, decomposing organic matter so it is ready sooner and can be applied to lawn or container soil.
Take the 4-by-8 foot plywood sheet and cut it in the middle with a circular saw. Keep one half aside and place the other one on a clear surface so you can work on it. Measure and mark this 48-by-48-inch piece into three equal pieces with a pen. Use a circular saw to cut over the lines. Two of these three pieces will serve as the back and front of the bin. Take the third piece and further cut it into two equal pieces that will serve as the ends. Take the other 48-by-48-inch piece and further cut it into two equal pieces that will serve as the base and the lid of the worm-composting bin.
Take one length of 2-by-2 lumber and cut it in the middle so you have two 48-inch pieces. Measure two 20-inch-long pieces from the other length of 2-by-2 and cut it. Drill all these pieces together to the edges of the base, using three galvanized wood screws per side. Measure and cut another 20-inch-long piece from the remaining length of 2-by-2 and drill it to the middle of the base to support it.
Drill 14 to 16 3/8-inch holes evenly spaced in the base.
Make corner blocks for the sides. Measure and cut two 14-inch pieces from one of the 2-by-4s, and two 14-inch pieces from the 2-by-2s. Place the 2-by-2s flush against the top edge of the front side and drill them in place. Repeat the process with the 2-by-4s, drilling them into place in the backside of the bin.
Hold the front side with its attached corner blocks and place one end to it. Make sure the tops of both are flush against each other and drill galvanized wood screws to attach them together. Hold this structure as you attach the backside to it with wood screws, and then attach the other end. You will now have a box without a base or lid. Attach hinges to the 2-by-4 corner blocks on the backside of the bin.
Turn this unit upside down so the base-side faces up. Place the base on the edges of the corner blocks and secure it into place by drilling galvanized screws to hold it together.
Measure, mark and cut the 2-by-4 so you have two 51-inch-long pieces and two 18-inch-long pieces. Lay these pieces to form a rectangle and place the plywood lid over them. Attach the lid to the frame with galvanized screws.
Place the lid over the bin. Extend the hinges from corner blocks of the backside to the back edge of the lid.