If you want to give your garden a dose of fertilizer and bulk up the soil with organic material, adding composted manure is an effective way to do it. Composted manure gives your plants nutrients and can improve drainage. If you don't have farm animals, you can obtain free manure from farmers in your area. Compost it yourself or ask if theirs is already composted.
Dig your garden space in the fall anywhere from 8 to 12 inches deep. Pull spent vegetable plants and clear rocks and other debris from the soil.
Spread a 2-to-4-inch layer of well-composted manure over the surface of the garden.
Let the manure remain on the surface through the fall and over the winter. As rain comes and snow melts, the nutrients in the manure will begin to leach into the soil.
Mix the manure thoroughly into the soil in the spring once the ground has thawed. You can add more composted manure at this time; work it into the soil immediately.
Plant your vegetable or flower garden. If some of your plants benefit from mulch, you can substitute composted manure. Do not pack the manure against the stems of the plants; the nitrogen could burn them.