In many new housing developments the topsoil has been scraped away and sold, or heavy equipment has compacted the soil. You can help correct your soil's deficiencies by adding soil amendments such as compost, manure, peat moss and other organic material. Inorganic amendments – such as sand, phosphorus or gypsum – may also be necessary. Broadcast amendments over the soil to a depth of 2" to 3".
Your soil may also benefit from the addition of a slow-release fertilizer. Greensand, a popular amendment, contains potassium, iron and other nutrients necessary for healthy plant growth. Gypsum supplies calcium and is said to loosen clay soils.
Once you've broadcast the amendments over the soil, use a rake to distribute them evenly. Use a rototiller or cultivating fork to incorporate them. Dig into the soil as deeply as possible: at least 12" to 18".
Never dig or till wet soil – you could destroy its structure. Hold a ball of soil in your hand and compact it. If it crumbles easily, you can cultivate the soil. If the ball stays compacted, it's too damp, and you should wait another day or two.
Once you've incorporated the amendments, you're ready to plant.