What Is Core Aeration? The benefits of Core Aeration are tremendous. It gives your lawn a chance to breathe again, allowing more oxygen, nutrients, and water to be absorbed and spread out across your lawn. This is why Core Aeration and overseeding go hand in hand, the seeds drop into the plug holes and receive exponentially more amounts of nutrients, water, and oxygen, allowing the seeds to germinate faster and more efficiently providing a thicker lawn and better root systems. It also helps loosen up hard or compact lawns from foot or paw traffic.When to Core Aerate? The best times for Core Aeration in Iowa are in the spring and fall. To most people’s surprise, late summer/early fall is the best time for overseeding as the seeds germinate faster in the warm days and cool nights. It is also possible to seed in the spring, however, this is most often less successful.Why Core Aerate and overseed? Core Aeration relieves soil compaction and helps prevent thatch build-up. Avoid using Spike machines as these tend to compact the lawn even more, look for the machines that actually bring up “plugs” that are around 3” deep and the size of your finger. If an area of your yard is worse than the rest, run the machine over this area 2-3 times and then overseed.