Spring Fever March 31, 2010 By Ty McClellan

Many courses were riddled this year with snow mold disease outbreaks coming out of winter. Fortunately, fungal pathogen activity has generally been limited to the turfgrass leaves meaning that the damage is primarily cosmetic. Therefore, the turfgrass should improve with time. 

The 2010 golfing season is underway across the upper Mid-Continent Region. With daytime highs consistently reaching into the 60’s and 70’s for nearly two weeks now, soil temperatures have risen to around 50°F. Although the cool-season turfgrasses have greened up, and putting greens have been mowed at least once, they probably are still several weeks away from the 60°F threshold that is necessary for vigorous growth and recovery.

Given the favorable weather of late, golf courses have reported an increase in the number of rounds played when compared to this time in recent years. It will be important to keep in mind that the fairways are not yet ready for daily cart traffic, albeit limited cart traffic may be tolerated. It is best to rely on your superintendent’s direction. Walking the course is an even better option, as it increases the level of exercise while helping preserve turf conditions in the fairways for the primary golfing season.

As golfers and golf courses alike prepare themselves for the peak of the season, this is an excellent time to review a few of the most discussed topics in recent weeks. They include the following:

  • Winter Injury

A number of superintendents expressed concern regarding winterkill and the potential damage this year and, unfortunately, those fears were confirmed in late February and early March when the snow and ice receded. Given that winter injury can be very complex and difficult to understand, we are oftentimes unable to determine exactly when damage will occur, and sometimes it is difficult to identify the specific type of winterkill injury. Furthermore, decisions are not always clear regarding techniques to help prevent winter injury including whether or not to utilize covers, to remove snow and ice from the greens in late winter, or to help facilitate the melting process. This winter was especially confusing, as there appears to be little rhyme or reason why some greens suffered severe or complete injury and others did not. Even greens with similar micro-climates on the same course are not showing consistent winter injury symptoms, and the comparisons only become more difficult from course to course or between greens built using different construction techniques.

Given the severity of winter injury, the Chicagoland superintendents collaborated in an effort to identify what worked, what did not work, and if there were any consistencies to specific causes of injury. Generally speaking, and not surprisingly, areas most often damaged included chronic problem areas that were already weakened and predisposed to injury, such as shaded environments, those suffering from poor drainage, those with concentrated traffic, or areas on north-facing slopes.

Looking forward, the best approach for dealing with winter damage is to exercise patience. In the very worst cases, a temporary green should be established so that the damaged green can be sodded or overseeded and allowed to recover without being bruised continually by foot traffic. In cases where the damage is only moderate, the greens can be left open to play; however, the cutting height should be raised and hole locations kept away from damaged areas to the extent possible. To expedite the recovery process, a number of superintendents are utilizing covers and dark-colored agents, such as black sand or Milorganite, to raise canopy and soil temperatures. In fact, topdressing with black sand in the spring is proving to be very effective in speeding spring green-up on greens traditionally slow to do so. For more information on the use of black topdressing sand, see a recent regional update on the Internet at the following address: 

  • Snow Mold Recovery

Given very favorable conditions this winter for the development of pink and gray snow molds, the resulting damage was alarming, to say the least, in some instances. This was especially the case in low-lying areas with poor drainage or for turfgrass stands dominated by Poa annua. Fortunately, the pathogens were generally limited to the turfgrass leaves so damage has primarily been superficial. In most cases, curative fungicide applications were not necessary and the turfgrass has already grown beyond the snow mold damage.

  • Poa annuaSeedhead Suppression

An application of tank-mixed Proxy and Primo must be properly timed for the greatest suppression of Poa annua seedheads on putting greens. This, however, can be difficult, especially with the occasional wide temperature swings that are common during late March and April. A few of the more successful approaches include scouting for seedhead emergence in indicator areas (i.e. where seedheads first emerge on south-facing slopes or in higher cut turf such as collars, approaches or fairways), checking for the "boot" stage, or basing applications on growing degree days (base 32 or base 50). Another very simple and reliable option is to make the initial application soon after the second mowing, with a repeat application three weeks later.

  • Fairy Ring Suppression

Fairy ring activity on putting greens has emerged as a growing concern for superintendents over the last two years. Fortunately, research done at North Carolina State University has identified a very effective preventative protocol that achieves season-long control of fairy ring in most instances. When soil temperatures consistently reach 55°F at a 2-inch depth in the spring, making two applications of Bayleton 50DF at the rate of 1 ounce per 1,000 square feet at 21- to 28-day intervals is recommended. These preventative fungicide applications must be immediately irrigated with 1/8- to 1/4-inch of water. Knowing the depth of fairy ring activity is important as more or less water can provide the best control.

  • Core Aeration in the Spring

A concerning trend has been the number of golf facilities that have already or are considering rescheduling spring core aeration away from mid-May to an earlier date in April. If maintaining a pure stand (or at least a high percentage) of creeping bentgrass is desired, then May truly is the ideal time for completing core aeration. The soil temperatures are more likely to be in the 60 - 65°F range so that the open holes heal most rapidly ensuring golfers experience the least disruption to play. Low soil temperatures in early April slow turf recovery and provide Poa annua with an excellent opportunity to invade. If you have moved away from the traditional timing for core aeration, it may be time to readjust the golfing calendar so this important cultural practice can be performed at the appropriate time. A great article detailing the importance of timing for core aeration in the spring can be found on the Internet at the following address:


If you would like more information about a Turf Advisory Service visit, do not hesitate to contact either of the Mid-Continent regional offices: Ty McClellan at or (630) 340-5853 or Bud White at or (972) 662-1138.