In addition to fertilizers, lawns also need a healthy dose of complex, composted organic material in order to thrive. Topdressing allows the soil-bed to be built slowly, over time, which eliminates costly re-sodding. Many homes do not have their lawn prepared properly when under initial construction, which leaves the roots close to hard-pan clay and other nutrient deprived soils. Topdressing a few times a year can effectively replace the layer of top-soil that was removed during the preparation of the lot.