The meteorologists tell us that much of the Southeast experienced the coldest temperatures in the last 20 years. Many low temperature records were broken for on the nights of Jan. 5 and 6. Most bermudagrass putting greens in the region that experienced the coldest temperatures were protected with straw and covers, but large areas of bermudagrass on tees, fairways and roughs were exposed to temperatures between zero to 10 degrees. These temperatures are capable of causing significant damage to bermudagrass. This update is designed to help equip superintendents with resources to answer the many questions they will receive from golfers.
Defining the Terms
Winter injury is a catch-all term that includes several different types of damage to turf in the winter including low temperature kill, desiccation and traffic. Low temperature kill is the biggest concern following this recent cold wave.
For more information, please see Winterkill and Responding To It Now, an excellent document on winter injury and diagnosis written several years ago by Drs. Grady Miller and Bert McCarty.
Assessing Damage
There is no way to quickly assess how much damage has occurred because there are a number of stress factors that may be involved including traffic, shade, excessive wetness, weak turf heading into autumn, aspect (north- or south-facing slope), etc. Taking plugs from suspected damaged areas and growing them indoors is the best method for assessing damage. Drs. Grady Miller and Bert McCarty offered the following tips in the article previously mentioned:
- Collect turfgrass plugs using a cup cutter from suspected low-temperature damage areas.
- Place or plant these plugs in a suitable container of native soil with drainage holes.
- Place the containers in a greenhouse, or in a room beneath a heat lamp or grow light, or as a last resort, in a southern-facing window.
- Keep the turfgrass plugs adequately watered.
- Note that turfgrass should initiate growth and greening within seven to 10 days.
- Assess the amount of greening after plugs have been grown for two to three weeks. Suspected areas with less than 50 percent greening should be considered extensively damaged from low-temperature exposure and will probably require renovation. Lesser damaged areas may recover with proper management practices and extra attention.
- Repeat the above sampling procedure on a 14- to 21-day interval through the periods of potential cold weather injury.
Stay in Touch
We are available by phone or email to discuss this topic and we welcome the chance to be of assistance to your course.
Source: Patrick O'Brien (patobrien@usga.org) and Chris Hartwiger (chartwiger@usga.org)
Information on the USGA’s Turf Advisory Service
Contact the Green Section Staff