The bitter cold winter was hard on bermudagrass, a warm-season perennial used extensively in sports fields and golf courses

“Reports have surfaced from all over Kentucky about winter-damaged bermudagrass,” said Gregg Munshaw, extension turf specialist with the University of Kentucky College of Agriculture, Food and Environment. “Low lying and wet areas, north facing slopes and high traffic areas have resulted in the greatest losses, but losses have certainly been found in almost all situations.”

While it may not be lush and green now, damaged bermudagrass may recover this summer. Turf managers need to assess the amount of grass that is damaged. Bermudagrass can rebound with adequate nitrogen fertilization if there is at least one live plant per square foot, especially if using an aggressive cultivar. Depending on the amount of winterkill and cultivar, it may take a couple of months for the grass to fully recover.

“For high school athletic fields that may not need to be fully grassed until mid- August, building upon the surviving bermudagrass is certainly an option,” Munshaw said.

Munshaw and turf specialists at Western Kentucky University conducted a study in 2013 to determine how quickly bermudagrass can recover with varying rates of nitrogen. They used nitrogen rates of 1, 2 and 4 pounds of nitrogen per 1,000 square feet on seeded and vegetative cultivars. The researchers found that when both types of bermudagrasses were planted on July 15, they covered the ground by late August.

“The higher nitrogen rates resulted in quicker establishment, but they also had the most amount of winterkill this spring,” he said. “Two pounds of nitrogen results in quick cover and has little effect on winter survival.”

Depending on the amount of winterkill on their course, golf course managers may need to act fast since the season is already in full swing. They may need to reseed or replant affected areas. Munshaw encourages managers to select vegetative or seeded cultivars with cold tolerance, such as the vegetative varieties Latitude 36, Midiron/Midlawn, Northbridge, Patriot, and Quickstand and the seeded varieties Riviera and Yukon. This will help prevent winterkill in future years.

More detailed information is available on the UK Turfgrass Science blog at http://www.uky.edu/Ag/ukturf/5-27-14.html.