We can all agree that showing up to the course and seeing that the greens have been aerated isn’t a welcome sight. Before you start grumbling about the grounds crew, realize that they aren’t psyched to have to do it, either. Removing hundreds of small cylinders of soil makes the course look worse, and temporarily makes sweet-rolling greens a whole lot less sweet. But they do it because they know it’s a necessary evil.
The USGA says, “Aeration primarily is performed to control organic matt – i.e, decaying roots and grass stems – relieve soil compaction, stimulate root growth and improve drainage.” So basically everything that makes greens good relies on aeration.
If your grounds crew didn’t aerate, the ground would hold water after rain instead of being able to drain it. Think about the 2016 PGA Championship at Baltusrol. That first huge rain storm that came through drained out nicely. If the grounds crew had never aerated, the course would’ve been so wet it would have been unplayable and we could’ve been looking at a mid-week finish instead of on Sunday.
Aeration saves the turf from itself. Too much organic matter can lead to issues related to how the grass grows. Aerating creates space for roots to grow, making the grass stronger and healthier. It also reduces the chances of disease occurring. If you’ve ever been at a course where disease has taken hold of the greens, you know how bad it is. With the right weather and the right disease, greens can be lost weeks. Aeration helps keep this nightmare scenario from happening.
If greens were allowed to grow without ever being aerated, they’d be softer. Softer greens would mean more punch marks, which are ugly and damage the grass. But it would also mean it’d be tougher to get the greens faster. No one wants to putt on slow, soft greens that are littered with punch marks.
So, yes: Aeration is annoying and makes for some questionable putting for a few days. But without it, your greens would be a complete mess.