There is still plenty of residual winter injury affecting playing conditions at numerous courses across the upper Midwest. The exceptionally slow recovery of winter damage last year and again this year due to unusually cool spring weather sure makes you wonder just what proponents of global warming are referring to.

The creeping bentgrass in old bent/Poa greens usually requires several consecutive days of temperatures in the mid 80’s accompanied by mild nights before a consistent rate of vigorous growth occurs. Much of the Region experienced nighttime temperatures cold enough to produce frost delays well into late May and early June. Only recently has the growth rate of bentgrass begun to approach the growth rate of Poa annua. Golfers have suffered through several months of thin, bumpy greens and their patience is wearing thin.

Plugging out the largest of the bare areas on greens is about the only good option available now that warmer, more humid weather has finally arrived. Some courses continue to seed into large areas of damage thinking that the warm weather will finally provide the right conditions for rapid germination and establishment. However, the frequent irrigation employed to keep the seedbed moist during July and August can create ideal conditions for algae.

Once algae gains a firm foothold on a thin green, the warm weather and frequent watering makes it difficult to control. Dry out the greens and the new bentgrass seedlings disappear. It’s a Catch 22 that has many superintendents wondering why they didn’t just plug or sod the damage earlier. Mancozeb and chlorothalonil can be used to slow down the growth of algae. A light dusting of sand to cover and shade the algae can be helpful as well.

Two consecutive years of extensive winterkill has more than a few old courses considering the options of rebuilding or regrassing greens despite the considerable expense and down time associated with either project. A good discussion regarding why some greens need to be rebuilt can be found on the USGA Web site.

http://www.usga.org/course_care/articles/construction/greens/Determining-the-Need-for-Reconstruction

An excellent article that discusses why some greens can be resurfaced and why others need to be completely rebuilt can be downloaded from this link.

/content/dam/usga/pdf/imported/060101.pdf

Schedule a Turf Advisory Service visit to document the need for putting green renovation and to help determine the best option, resurfacing greens or rebuilding greens, for your golf course. There is still time to arrange a visit this season, call the North Central Region Wisconsin office for the next available date.

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