To give you an idea of why we have recently top-dressed our greens here is a great article from Grounds Maintenance.....
Topdressing has become standard in golf course management. For years, many golf course superintendents practiced heavy topdressing in the spring and fall after core aeration. In the last 10 to 15 years, many of them have switched to lighter, more frequent sand topdressing in their greens management program.
Research has shown that greens that are not topdressed have poorer turf quality than those that are topdressed as little as two times per year. Greens that are not topdressed become thatchy and puffy, and can result in scalping and shorter ball-roll distances.
Topdressing has several benefits. It * Produces a smooth, firm putting surface. * Reduces the thatch layer. * Allows reduced mowing heights. * Protects the crown. * Increases ball-roll distance.
With the continued demand from golfers for greater ball-roll distances, superintendents have begun topdressing more often throughout the growing season. Light, frequent topdressing is defined as application of 2 to 3 cubic feet per 1,000 square feet of material every 10 to 14 days throughout the growing season. It is believed that this level of topdressing will provide a smooth, firm and uniform surface, resulting in longer ball-roll distances.
Topdressing is increasingly important on greens using the newer, aggressive bentgrass cultivars. These bentgrass cultivars produce a denser canopy and turf that is thatchier than the older bentgrass cultivars. The greater resistance to the ball as it rolls over the grass blades may result in shorter ball-roll distances. Shorter ball-roll distances and thatchy turf surfaces are not acceptable to today's golfers. They want smooth, firm and fast surfaces for putting.
Adding inches to ball roll In-depth research on topdressing and ball-roll distance has been limited to just a few projects. Much of the research that involves golf green topdressing deals with thatch management and topdressing materials. But, the studies that deal directly with topdressing's effect on ball-roll distance can provide a better understanding of how topdressing can improve ball-roll distance.
How much added distance should a superintendent expect to see from topdressing? Research indicates that ball-roll distance difference would have to be at least 6 inches greater-and more likely closer to 12 inches greater-for a typical golfer to notice a difference. Anything less would not warrant the added effort and expense of increased topdressing because few players would detect the change. You should increase the topdressing frequency only if it significantly increases the quality or health of the green.
A University of Nebraska study has shown that greens topdressed seven to eight times during the growing season at 2.7 cubic yards per 1,000 square feet p roduced significantly longer ball-roll distances than those greens topdressed in the spring and fall at 10.8 cubic feet per 1,000 square feet. The ball-roll distance of the light, frequent topdressing program was 8.1 feet compared with 6.9 feet for the twice-yearly topdressing program. Both had nitrogen applied at 2 pounds per 1,000 square feet per growing season.
Other factors Not only is frequency of topdressing important, you also must allow the topdressing to be worked into the surface. Verticutting opens the turf so that the topdressing can easily settle in. But don't overdo it.
Researchers in a University of Nebraska study conducted on several golf courses in Nebraska, South Dakota and Iowa, found that a moderate frequency of verticutting and topdressing-two to six timesper year-was preferable to a more aggressive program of 12 to 16 times a year.
The more aggressive program caused continual disruption of the surface of the green, so a smooth surface never formed. But moderate topdressing and verticutting allowed the topdressing material to be worked into the canopy to produce a firm, smooth putting surface.
Research at The Pennsylvania State University supports the conclusion that the topdressing must be worked in to achieve a smooth putting surface. Researchers found that both light and heavy topdressing decreased ball roll distance initially. But after topdressing material had time to work itself into the canopy, ball roll distance increased.
For the first eight days, a ball lost up to 5 inches of roll with light topdressing and 9 inches with heavy topdressing. But after the topdressing material worked itself into the canopy, ball roll increased 6 inches with light topdressing and 15 inches with heavy topdressing.
For this reason, you should apply topdressing material 10 to 12 days before you want the surface to achieve its best surface (for member-guest or other big events). This gives the topdressing material enough time to settle into the turf. Dry topdressing material will easily settle into the turf canopy with just a light brushing or light irrigation.
Is it worth the effort? Topdressing provides a better surface for ball roll because it creates a firm, smooth, uniform surface that exerts minimal resistance on the ball as it rolls across a green. Rather than applying topdressing material heavily at the beginning and end of the growing season and hoping that it provides an adequate surface throughout the golf season, light, frequent topdressing has been used to provide a better surface to putt on throughout the growing season.
Golfers can play on greens managed with a light, frequent topdressing system right after topdressing applications. Playing on greens managed with heavy, infrequent topdressing is difficult right after applications because they have a thick layer of sand that needs to be worked in. Also, piles of sand often persist for up to four or five days after applications.
When considering more topdressing to improve ball-roll distance, you should keep in mind the average golfer's ability to detect a change of ball-roll distance. Most likely the change would have to exceed 6 inches, and probably be closer to 12 inches, before a golfer would be able to notice.
Increasing ball-roll distance by 5 or 6 inches by increasing topdressing frequency from six to 10 times per year probably would not be a sound financial decision unless you were seeing improved turf quality or health. The added time and money spent on the four additional applications would not give you a significant increase in ball roll distance.
A good rule to follow for topdressing greens to get maximum ball roll distance and highest green quality is to topdress at a light rate once a month during the growing season.
Anne Streich is an extension horticulturist and Dr. Roch Gaussoin is an extension turfgrass specialist at the University of Nebraska (Lincoln, Neb.).