Compaction
Soil compaction is a problem which develops naturally under many conditions. Heavy soils and heavy traffic zones are particularly subject to compaction. If soil is trampled, especially when it is wet, compaction will very likely occur.
To relieve compaction without excessive injury to grass plants, an aerator should be used. They usually have prongs or knives which pierce the sod to a depth of 2 to 3 inches, or they have hollow tines that extract plugs of soil. In either case, the effect is to open up or “aerate” the soil, allowing water, air, and nutrients to reach the grass roots.
The best time to aerate is late summer or early fall. However, if your soil is compacted in the spring it may necessary to do it at this time. Also, try not to aerate during high heat or drought periods since it will accelerate the moisture loss from the soil.