The damage done to greens last summer and this winter has been well documented in regional updates, webcasts (https://www.livemeeting.com/cc/usga/view?id=CDP6H3), and local golf publications. Progress is being made at some golf courses with a material to help greens recover from winter damage – black sand. Before the preliminary results are discussed, some background information is needed.
Researchers have shown that the use of properly-sized USGA sand can warm the putting green surface in a manner similar to turf covers. When combined with covers, the temperature increase at the turf canopy is even more dramatic. Also, for courses with ice coverage or extended snow coverage, the advantages of using an inert, dark material to rapidly remove snow and ice have been documented. But what about Poa annua-dominated greens found in a much milder climate? Will black sand improve the recovery on greens, or simply be a waste of money with covers remaining the best answer? Based on what has happened at two golf courses in British Columbia and Oregon, the use of black sand as a recovery enhancer deserves a close look for courses that still have weakened greens.
Marine Drive Golf Club is located in the lower mainland of British Columbia, with a mild climate similar to Washington and Oregon. Their greens took a major hit this winter, with natural recovery starting in late January-early February from the ongoing El Nino weather pattern. In early February, they decided to "jump-start" their greens with the application of 300 lbs./1000 sq. ft. of black sand from a source in Idaho, and they seeded bentgrass after spiking. When discussing the use of this product, Superintendent Wade Hawksworth was very positive about the money spent, and sees the additional benefit of smoothing the Poa annua surfaces. Thus far, the results have been very good, with the membership observing a very visual effort to improve the greens. Wade estimates that he will open several greens at least two to three weeks earlier than if the darkening agent was not used.
Another example is Illahe Hills Country Club, located in Salem, Oregon at the northern part of the Willamette Valley. As with his counterpart to the north, Superintendent Bill Swancutt applied black sand (400 lbs./M) on some of his worst areas, and he also had the foresight to place a piece of plywood down before sand application. The photo shows the distinct difference in color and regrowth compared to the grass under the plywood-covered check plot. Mr. Swancutt reports an expected two-week faster recovery of his worst greens.
These examples do not in any way imply that turf covers should be discarded in the recovery process. Marine Drive GC used both covers and black sand on some of their worst greens with even better results, while many other golf courses in western Oregon and Washington have had very good recovery with covers only. However, for courses that may have only a portion of a green that is damaged, and they do not wish to deal with how covers will impact play, the use of black sand offers another way to enhance recovery without daily cover removal and replacement. For superintendents facing a similar situation, this may be the first time that "black layer" has ever been discussed in a positive light.
Source: Larry Gilhuly, firstname.lastname@example.org or 253-858-2266