Preventing Winterkill with Data Loggers

Winter Damage Initiative Group
Extreme weather conditions can make the task of a greens management at golf courses more challenging than ever, so golf course superintendents turn to data loggers to help prevent the type of greens damage known as winterkill.

Over the past few winters, many golf courses in the United States have been subjected to some of the most extreme weather conditions they’ve seen in decades. As a result, many golf course greens have suffered from severe turf damage, making the task of greens management that much more challenging for superintendents.

Steve Thys, superintendent of the Worcester Country Club in Massachusetts, is a case in point. Two winters ago, Thys did a routine check of one of his greens after snowfall on an already covered ground. According to Thys, “Everything looked as lush green as it had in November because it had not hardened off by the time the first snowfall fell.” Just a little over a week later, he checked the green again, only to find winterkill.

“Something happened during those ten days, but it was impossible for us to pinpoint any specific weather occurrence,” Thys explains. “Nevertheless, we had a big problem on our hands, and it was a race against time to get the damage repaired since our members flock to the course the minute the snow melts.”

Thys’ story is a common one. So common, in fact, that he and other superintendents are beginning to monitor greens in the off-seasons with battery-powered data loggers.

Data loggers demystified
Data loggers are low-cost, compact instruments that incorporate built-in micro-processing, high-accuracy temperature sensing, and battery power in a rugged enclosure designed for long-term deployment outdoors. Loggers can be placed under turf covers during the winter months, where they will collect temperature data at user-defined intervals (e.g., every 10 minutes) and store it digitally into logger memory.

In the wide spectrum of computer-based technologies that superintendents rely on, data loggers are perhaps one of the simplest and most straightforward. Using them involves four basic steps: logger setup, deployment, data retrieval, and analysis.

Setting up a logger is typically done by connecting the device to a computer and using accompanying logger software to make a number of point-and-click selections. These include how often the logger should take a turf temperature measurement, and the specific date and time the logger should start recording. Deployment involves determining optimal placement of the logger on the green and physically installing the logger under its covering. Data retrieval can be accomplished manually, where the superintendent offloads the collected data onto a computer, laptop, or data shuttle, or, in certain cases, automatically, where the logger transmits the data to a computer via wireless communications. Automatic data retrieval can be an important benefit in situations where the superintendent needs immediate notification of course conditions. Analysis of the data is typically performed using the accompanying data logger software, which allows the superintendent to quickly and easily translate the data into time/date-stamped graphs that show spikes and drops in turf canopy temperature over the given data collection period.

Understanding root causes
“Here at Worcester, there are a lot of variables in terms of the weather, so we need as much data as we can get to figure out why and when our annual bluegrass has been checking out on us,” explains Thys. “Our highest green is at an elevation roughly 200 feet above our lowest one, so they have very different wind and sunlight exposures. By monitoring temperature 24/7, we’ll be in a better position to prevent damage from occurring. For example, the data might tell us that we need to break up ice formations and let the turfgrass breathe, or that we might need to apply a top-dressing material if the situation calls for it.”

According to Peter Hasak, superintendent of Tedesco Country Club in Marblehead, Massachusetts, the winterkill problem over the past several years is forcing superintendents to look for new tools and techniques. “Traditionally, winterkill is something we’d typically experience to some degree every few years. But during the winters of 2001, 2003, and 2004, the problem was very widespread, and many courses got hammered. Our research shows that, depending on the dormancy of the turf, a temperature of even a few degrees below zero can in and of itself cause turf damage. So we really need tools to get a comprehensive snapshot of what’s going on during the winter months and get that much more specific. This will not only help us manage our greens better, but it will put us in a position to be able to tell our memberships and boards what is happening out there on the course.”

Hasak has been experimenting with data loggers and various types of greens covers to understand the differential temperatures above and below the cover surfaces and to correlate that data with potential damage to the greens. He says that the loggers he is using – HOBO® Pro v2 loggers from Onset – have reported temperatures of up to a turf-threatening 90°F under some impermeable covers during late February.

“While we’ve typically been using translucent covers that let a lot of sunlight in, we are looking at making the change to solid white covers in some areas,” he explains. “The idea of bringing solid white covers into this part of New England is relatively new, but it’s an idea worth considering in certain situations.”

Time for a change
Hasak, Thys, and other superintendents have recently formed an initiative called the Winter Damage Initiative Group to combat the severe effects of winterkill. The group will focus on techniques such as data logging to better understand the causes of winterkill.

“A bunch of us got together and decided we need a specific course of action,” Hasak explains. “So this coming winter, we’ll all be monitoring our greens and sharing data with one another.”

Turfgrass scientists from the University of Massachusetts and University of New Hampshire will also be helping to stop the winterkill epidemic. They will be conducting in-depth analysis of turf plug samples taken from various courses and comparing what they see with temperature records.

“In our business it’s very much like a fraternity where we are all looking out for each other,” says Thys. “There are no easy answers to this problem, so it’s going to take the work of many to reach some useful conclusions.”