Monday 13 April 2015

Turf Grass Health: Winter Kill

We have had a few comments lately about the course being very very dry. I wish I had been able to sit down and address this issue earlier, but until now we have been busy just trying to keep the course from getting too dry.

We have been waiting to be hooked up to the city effluent water, as we do every spring. This spring we had an exceptionally early snow melt, allowing us to open the course early (Woohoo!). Usually we do not need to begin irrigating the course until early April, but the early melt this year required irrigation to start by mid March. We have been bugging the people from the City who are involved with getting the effluent going and they were trying their best to get us water earlier than usual, but as I understand, chlorine was back ordered and delayed the process about two weeks.

We are able to pump a small amount of water from the river into our irrigation pond, (thanks to our Links Director, Robin Johnson) but until we are hooked up to effluent water, our system cannot run to its full potential and we cannot irrigate overnight. We can manually irrigate during the day, using a hand held radio (walkie talkie) to communicate with our central irrigation system, but this becomes difficult as more and more people are on the course golfing. We irrigate in the priority of greens, tees, dry fairway areas, fairways, and then everything else. 

A few people were concerned that we were losing turf on fairways and tees but I can assure you, these areas were already damaged, they were damaged before the snow even melted. We are not able to see this damage until the turf around these areas begins to grow and green up, leaving areas of brown and white turf very visible. These areas are known as "Winter Kill" and can are caused by a number of different factors:

  1. Ice damage - Thaw and freeze cycles during the winter cause ice to accumulate in low lying areas, especially on fairways.The ice suffocates the turf, causing a build up of toxic gases like carbon dioxide. You can see the result of this in many low-lying areas on the fairways.
    Low area, ice damage (anoxia)
  2. Crown Hydration - This occurs when water, either from snow melt or rain, accumulates and rapidly freezes. The plant is essentially tricked by the water available and begins breaking dormancy. As the plant takes in water and if the temperature rapidly drops, the freezing process causes the water to expand as it forms ice and breaks the plants cell walls, much like a frozen glass bottle full of water. Some of the damage you see in low lying areas may also be caused by crown hydration.
    Ice formation beneath snow cover
  3. Dessication - This is just a fancy word for removal of water. Dessication takes place when the turf is exposed to the elements for long periods of time. Snow cover is blown off of an area and over time, the wind and sun cause the evaporation of moisture stored in the plant. After a certain amount of time the plant becomes too dry and dies. You can see this type of damage on some of the high mounded areas of the fairways or on elevated tees.
High and Dry - Dessication area
The good news is that the type of grass we have on our fairways is mainly "poa annua" which is actually an annual plant. Much like the annual flowers in your garden, poa is supposed to die each winter. To ensure its survival poa produces millions of seeds in the fall to re-seed itself in the spring, and then has another episode of mass seed production in the late spring to ensure its survival after the heat of summer.

Areas like this will fill back in quite nicely with warmer weather and fertilzer
Now that we have effluent water (hooked up on April 10th, yay!) we are able to supply enough water to these areas that require some extra maintenance. Once we get some warmer weather, the poa seeds from last fall will begin to germinate and fill in the damage. We have already aerated these areas to allow for better penetration of water, air and nutrients into the soil. We have applied an initial application of fertilizer and will be continuing with more to help these areas fill in faster. We also try and overseed some of the chronic areas with bentgrass, which has a better tolerance for ice, to help prevent future damage.
Aerated fairway areas, allows water and and fertilizer to reach soil easier

Although the course was very dry, the damage you see is from winter kill, not from being too dry. With our maintenance practices and some warmer weather I can assure you that with in a month these areas will hardly be noticeable. We usually see some damage in the spring, this year, although it was a milder winter, we still had quite a few freeze-thaw cycles causing a bit more damage than we have seen in the last few years. If you ever have any questions about the course, please feel free to stop by my office or track me down on the golf course, I always enjoy a good conversation about turf! If you would like to read more about winter damage in Canada, please click this link: Winter Kill

-Travis