It never hurts to remind golfers why greens need to be cultivated once or twice a year, especially in the north where the seasons are short and the open holes are a source of annoyance to golfers for a week or so during prime play time.

Hollow tine core cultivation is one of the more effective ways to manage the natural accumulation of organic matter in the upper root zone of greens when the cores are removed and the open holes are filled with sand. A light, frequent sand topdressing program will help dilute new organic matter production, but it only buries old layers of thatch in greens. It's the coring that removes old thatch. The holes encourage the rapid movement of water into the playing surface and though the soil profile. In a nutshell, coring greens ensures a healthy balance of air and moisture in the root zone.

Unfortunately, there are a small but increasing number of courses that believe the benefits of aeration are not worth the temporary annoyance to golfers. Some have substituted deep tine aeration for standard hollow tine aeration, and often the sand topdressing program is put on the back burner as well. This can be a recipe for disaster, especially when greens are managed aggressively for speed.

Several courses that decided to back away from coring and topdressing to appease golfers have paid a high price within three or four years - after a thin, but dense layer of organic matter appeared in the upper root zone. The problems tend to occur during a prolonged period of hot wet weather, when the putting surface seals off and roots die back. Once the stressed turf begins to thin out, a myriad of problems such as algae/moss encroachment and basal rot anthracnose can make the rest of the season miserable for both golfers and superintendents.

Granted, if you have layer-free new greens or old greens that have been topdressed religiously for many years there may not be a pressing need for frequent core cultivation. These greens would have absolutely no concerns with layering, the presence of deep roots all summer, no soil compaction, and rapid movement water through the soil profile. Greens like these are few and far between.

It should come as no surprise that when disaster hit these minimal cultivation golf courses, their maintenance philosophy did a 180 degree turn. Greens were aggressively cultivated with deep vertical mowing and coring with holders that accommodate twice the normal number of tines. The disruption to the greens increased dramatically during spring and fall.

No doubt there are exceptions to the rule - the course that maintains healthy putting surfaces with frequent topdressing instead of core cultivation. However, when you consider the collective wisdom of the majority of superintendents at highly regarded courses in the Region who routinely aerate greens every season, you realize that they would not be including this operation in their management program unless it was an absolute necessity.

The bottom line - straying too far from the norm with respect to coring greens is risky business.

Source: Bob Vavrek, rvavrek@usga.org or 262-797-8743