Q: I understand the importance and benefits of aerating a lawn. However, this year my neighbor bought an aerator made with spikes on a drum. What do you think?
A: I think he won’t get much benefit from using a spike aerator. When a core aerator passes over a lawn, it pulls up thousands of soil plugs. The holes left behind have rough sides and their large interior surface gives lots of places for air and water to penetrate. Spike aerators tend to compact the soil because they just push the soil out of the way as they pass over. Golf courses sometimes use spike aerators but they do so because their soils are usually sand-based and the spikes break through the water-repelling black layer under the sand. In summary, lawn stabbing is not the same as lawn aeration.