Lawn aeration is the process by which the ability of lawn soil or the ground to circulate air is increased. Lawn aeration is typically done with a specialized machine called a lawn aerator. In compacted lawns, aeration improves soil drainage and encourages worms, micro fauna, and micro flora which require oxygen. Therefore, lawn aeration is important to augment and allow for increased organic composition of lawn soils.
Lawn aeration helps to mitigate lawn thatch, or the layer of dead organic tissue that deprives lawn of oxygen. It also lessens soil compaction that a) makes it difficult for grasses to root, and b) that reduces the natural amount of rainwater irrigation. Watering dense lawns or highly compacted lawns the night before can make it easier to aerate a lawn.
There are two types of lawn aerators. Core aerators have hollow tines and pull out plugs, or cores from the soil. The core is left on the turf. Soil compaction is reduced and the holes can remain open for a long time, allowing air, fertilizer, and water to reach grass roots to produce better growth. In addition, the soil plugs or cores left on the grass turf help to break down lawn thatch. Spike aerators create holes in the ground by pushing soil aside with wedge shaped spikes. The problem with this method is that soil compaction is increased, and the compacted soil around the holes can expand in a short period when exposed to water. The benefits of spike aeration are therefore short term compared to core aeration.
Professional lawn aeration is done with gas engine core aerators that are heavy but that can aerate a large lawn in short time making it cost effective for the consumer.