Although I have yet to see widespread winter injury in my travels, isolated pockets occur nearly every year and it is a common concern on golf courses throughout the Northeast. Turfgrasses in northern areas are susceptible to four abiotic types of winter injury: crown hydration, direct low-temperature injury, ice encasement and desiccation. The type of injury observed will vary depending on location and winter weather conditions. If the golf course is perfectly healthy when it goes dormant and key areas never wake up, it can be frustrating. Traffic often needs to be restricted on injured areas and the course may even need to close completely during recovery efforts. Although waiting for warmer temperatures to stimulate growth is necessary for recovery, assessing winter injury can be expedited.
Golfers and golf course maintenance staff want to know how the turf will come out of winter dormancy. Bringing a selection of turf plugs into warmer temperatures will stimulate growth and induce spring greenup or confirm the worst – that winterkill has occurred. One way to assess viability of plugs is to create a climate-controlled space with grow lights. I have seen simple setups consisting of plastic tubs with heat lamps to more sophisticated multilevel growth tents with thermostat-controlled temperatures. Even placing plugs on a sunny windowsill can work and help give you peace of mind, or alert you to a potential problem. When taking plugs from the golf course inside to the growth chamber, keep the plugs moist by watering frequently. Knowing if there’s damage is what’s important. That information will assist in planning and communicating to golfers what to expect during recovery.
Warm-season grasses generally require continuous nighttime air temperatures of at least 60 degrees F to induce any signs of spring greenup, with growth resuming when soil temperatures reach about 65 F. Cool-season grasses can start to green-up at much lower soil temperatures, as low as 50 F.
If the plugs from areas of concern break dormancy, then the waiting game becomes more palatable. If the plugs do not break dormancy, then planning for recovery can begin. Making sure putting green covers are on hand to stimulate growth and having seed and/or sod ready to go should take precedence. In addition, communicating what spring playing conditions will be like to golfers is highly recommended. Knowing that there are some weak or thin areas ahead of time and that a plan is in place to fix them can help ease concerns. If you have experienced winter injury, a regional USGA agronomist can assist with managing expectations at your course and developing a plan for recovery.
Northeast Region Agronomists:
Darin Bevard, senior director, Championship Agronomy – dbevard@usga.org
Elliott L. Dowling, regional director, East Region – edowling@usga.org
Brian Gietka, agronomist – bgietka@usga.org