Ahh...Fall pt. 2

My last post lead into what it really takes to "put a course to sleep for the winter".  In this post, I'll shed some light on what we do to put a golf course to bed for the winter.  I'm assuming that some of you out there understand that there is a lot of work that needs to be done to ensure that the grass will come back healthy and vibrant once the snow is gone.  I am going to outline the basic needs of winterization, and try not to be sooooo long winded as to lose your attention.

     With the cooling of temperatures, I explained that cool-season grasses start to grow at a elevated level in comparison to their activity levels in the heat of the summer.  But as the night temperatures drop into the 40's and 30's, a change takes place in the turf.  When these temperatures start dropping, the grass switches from shoot growth to root growth; storing much needed carbohydrates in their roots for the initial green-up the following spring.  There are a lot of differing philosophies as to how much is stored, but it is a good rule to put down Nitrogen in the fall to feed your roots.  Just like a black bear stores fat for the hibernation, grasses store carbohydrates for their hibernation.  The term hardening-off refers to the grass shoots slowing down to an almost non-growth state yet they are still actively storing nutrients for the upcoming spring.  Nitrogen is a key nutrient, but the other macro nutrient you can't overlook is Potassium.  K on the bag, usually potash, in your N-P-K ration found on fertilizer bags, will aid your turf in reducing stress.  Dr. Vargas challenges this and I admit that he changed my thinking on this subject.  A newer post clears this up.  Potassium plays a major role in winter hardiness and protecting your plants from disease.  Think about it this way:  A healthy human immune system will fight off infections and make the body run smoothly without interference from colds and flu.  The same basic principles can be applied to grass, even though it seems funny to think of a plant in this way.  Healthy, vigorous turf is better suited to withstand the various stresses and diseases that can pop up during the year.  K plays a huge role in the plant's cellular reproduction and protection, thus leading to a healthier plant.  There are unlimited resources that you can dig into about fertilization and fall applications and I encourage you to educate yourself if you want your home lawn growing like a country club.  There are many practices that you can follow on your home lawn (to a much lesser extent) like what we do here at golf courses. 
     Fertilization is huge, but blowing out the irrigation is something that every single golf course will do in the northern climates.  PVC will shatter when water that is left in the lines is allowed to freeze and expand.  If you were to put a sealed cup, full with water, into your freezer, it would no doubt expand and crack.  The same goes for PVC buried in the ground under 100+ PSI.  There are different schedules of PVC that go into a golf course irrigation system with differences in O.D. and I.D. pipe diameters.  There is a lot of sch 1120 on our course, which is the thinnest of the main three that are used.  I'm not a well-casing/irrigation contractor, but just from my experience with irrigation repair, there is a major difference between sch 1120 and sch 80.  Sch 1120 is the thinnest, with sch 40 being in the middle, and sch 80 being one of the thickest that we implement on our lateral lines off of the main lines.  Every irrigation repair that I have performed here at Wildflower has been due to burst pipe that was sch1120.  The PSI ratings change with the different O.D's (outside diameters) so ill use the most recent case in point.  We installed sch 40 2" O.D. pipe yesterday, and its max PSI rating was up into the mid 200's.  When you think about Wildflowers irrigation, our lines are under constant pressure of 100 to 125 PSI.  Sch 1120 is only just above the 125 PSI rating so any surge in pressure from water hammer or air will cause the pipe to weaken and burst.  Once again, there is an abundance of information of the differing pipe sizes and what best suits your application on the Internet. 
      Making sure that you get a majority of the water out of the lines gives you the best chance of making it through the freeze of winter with no water expansion in your pipes that leads to shattering.  We hook a huge air-compressor up to our lines and turn on each and every head to make sure there is a fine mist coming out of the nozzles.  Working the low spots on the golf course is key, because air will push the water to the lowest spots on the course, making the water sit in the lowest pipes on the course.  I have been told by irrigation contractors that air will compress up to 10x the amount that water can compress, so when you have 125 PSI in your lines, you could potentially have 1250 PSI if there was an instance of air getting to an end of a line with nowhere else to go.
     Fertilization, blowing out, topdressing greens, putting up snow fence are all some of the things that need to be done on the course before the ground freezes.  Before the snow flies there is another thing that golf courses must do to ensure there isn't a mess of mycelium (remember from my past posts-fungal spores) all over the turf.
     SNOW MOLD APPLICATION:
          One of the biggest preventative disease spraying times of the year is late fall just before the snow falls and stays on the ground.  In my earlier posts, I touched on the different snow molds that affect northern climate golf courses.  120 days is a good marker for the efficacy of fungicides targeting snow molds.  Snow molds look nasty in the spring and develop under cold, wet conditions.  There are other things that can reduce the turf quality over winter but snow mold is one of the diseases that can be limited by how well you cover your course in fungicides in the late fall.  There is also winter dessication, but I'll talk more on this during the winter months. 
    As you can see, there are many things that your golf course superintendent does in the fall to ensure you have a great looking golf course in the spring.  Next time you see your sup scrambling around late-fall looking like they are going in ten different directions, stop him/her and tell them thanks for all your preventative maintenance!!!!
             I don't have the time to delve deeper into all these procedures; I have to get out and start prepping Wildflower for another great year of golf!!!!