Some basic maintenance practices withstand the test of time. A good example is late-season topdressing applied to putting greens after they have received their final snow mold treatments and before the first significant snowfall. The goal of late-season topdressing is to protect the base of the grass plants from desiccation caused by winter wind.
Some superintendents agonize over the exact amount of sand to apply, but you don't need to be perfect to be effective. Err on the side of applying a little less sand if you are worried. You can always apply more sand before winter but you won't be able to easily remove it if too much is applied. However, avoid burying putting greens to the point that foliage disappears. Overabundant sand can migrate down slopes and accumulate in low spots to the point that it smothers turf.
The right amount of sand for late-season topdressing is somewhere between a light topdressing and what is required to fill aeration holes. If the application looks fairly uniform and turf leaves are showing, leave it alone. If not, a quick once-over with a soft brush or lightweight cocoa mat can even things out. Take care not to get overly aggressive with a brush trying to force topdressing sand into dormant turf. This isn’t the time to “sandpaper” winterized putting greens.
Even if too little sand is applied to achieve maximum wind protection, the sand that has been applied will still help dilute organic matter in the upper soil profile when turf begins growing in the spring. In fact, the additional benefit of a little thatch control is one of the overlooked benefits of late-season topdressing. However, do not expect one heavy, late-season sand application to compensate for an inadequate topdressing program during the growing season.
So, why worry about wind desiccation? Unlike ice suffocation or low-temperature injury that primarily affects Poa annua, desiccation is an equal-opportunity threat to all putting green turfgrasses. Frigid wind can freeze-dry exposed creeping bentgrass just as easily as Poa annua.
There is still time to add a late-season sand topdressing application to your schedule for the 2017 season. The positives far outweigh the negatives, especially if your putting greens have accumulated excessive amounts of organic matter.
Central Region Agronomists:
Bob Vavrek, regional director – bvavrek@usga.org
John Daniels, agronomist – jdaniels@usga.org
Zach Nicoludis, agronomist – znicoludis@usga.org
Information on the USGA’s Course Consulting Service