Dense, heavy clay soil makes gardening extremely difficult. Use this method to turn the clay into arable topsoil without hiring professionals or renting a backhoe. Gather a tiller, compost, garden soil, decomposed pine bark, rotted manure and wood mulch to handle the project.
Till the clay
Use a tiller to disrupt the top 12 inches of clay. If you don't have a tiller, use a shovel or gardening fork.
Add garden soil, compost and bark pieces
Cover the clay with a 9-inch mixture of equal parts rotting pine bark, mature compost and commercial garden soil.
Till and test the ground
Till the area until the soil, compost and bark are evenly distributed. Pick up a handful of soil, squeeze it, and open your hand. If the soil crumbles, it's the proper consistency. If it doesn't crumble, add more soil, bark or compost.
Add rotted manure
Spread rotted manure over the soil. Look for the heat-treated variety that has a milder odor and lower acid content than other types of manure. Avoid raw manure, which is extremely acidic and often contains viable weed seeds.
Top the soil with wood mulch
Cover the manure with a 3-inch layer of wood mulch. Don't mix the mulch into the soil.