In the world of gardening, rabbit manure plus vermicomposting equals bliss--for both gardeners and their plants. Using rabbit manure from hutch rabbits as a main ingredient in your worm compost bin produces a mild but nutrient-packed soil amendment rich in nitrogen from the alfalfa-based diet rabbits consume. Rather than collecting and transporting the rabbit manure from the hutch to the worm bin, George Dickerson, an extension horticulture specialist at New Mexico State University, suggests that you construct a worm compost bin directly beneath your rabbit hutches. The rabbit manure and urine fall directly into your worm bin, giving your worms a regular source of food to convert into castings, nutrient-dense worm droppings ready for application on your garden.
Measure the outside perimeter of your raised rabbit hutch to determine the board dimensions for the sides of your wooden worm bin. Write the dimensions down on a piece of paper. Subtract the width of the rabbit hutch legs from the total measurements to determine the lengths of the untreated 1-by-12-inch boards you'll need for the sides of your worm bin; this allows your worm bin to fit easily between the rabbit hutch legs. For example, if your raised rabbit hutch measures 3 by 5 feet and each hutch leg is 4 inches square, you'll need two 28-inch-long 1-by-12-inch boards and two 52-inch-long 1-by-12-inch boards.
Stand two of the 12-inch-tall 4-by-4-inch posts on end, parallel to one another. Position one of your side boards with its cut ends flush with the outside edges of the two posts. Nail the ends of the board to the two posts, using one galvanized 2-inch nail every 4 to 6 inches along the height of each post. Repeat this process to create the opposite side of your worm bin. You should now have two identical side pieces.
Lay the board for the front of your worm bin perpendicular to the two side boards. Make sure the ends of the front board are flush with the outside edges of the two corner posts before nailing it to the posts to create a U shape. Secure the back board on your worm bin in the same fashion, which should produce a bin with fully enclosed sides; the top and bottom of the bin should be open to allow rabbit manure to drop straight into the bin and excess rabbit urine to drain into the ground.
Slide your worm bin completely beneath your raised rabbit hutch. Fill it with 4 to 6 inches of damp, shredded newspaper and dead leaves before dumping your red worms into the center of the bin. Provide approximately 1 lb. of red worms (about 1,000 individual worms) for every two to three rabbits you have.
Scooop finished compost out with a hand trowel to harvest it.