Thursday, October 22, 2009

Playing Par with Jack Frost

By Charles B. White
Director, Southeastern Region, USGA Green Section

As winter begins, the golfer lays aside his clubs for a time and settles down to watch football. But, loving the game, our minds quickly return to golf, and our bodies avidly follow. Thus we encounter an age-old problem: morning delays to allow the frost to clear or enable the green surface to thaw. Often a confrontation arises between the golf professional and/or the superintendent on one side and club members on the other. Consider the problems of playing greens in the winter when frost or freezing occurs, and why play must be delayed, or even prevented, for a period of time.

Everyone knows frost must clear off the grass before play can begin, but few people know why. Frost on the grass blades tells us that the water inside the leaves is frozen. Remember that water is the primary component of plant tissue. When this water is frozen, traffic on the turf causes the ice crystals in the cells to puncture through the cell walls, killing the plant tissue. Little damage is done to the crowns (growing points) or roots if only a light frost appears; however, when the frost is heavy, cell disruption may occur at the crown, thus killing the entire plant. Frost damage symptoms include white to light tan leaves where traffic has passed. The simplest approach is to avoid traffic until the frost melts.

Another dangerous situation exists when the soil is completely frozen to the surface but the grass blades have thawed. Provided there is no frost or ice on the grass under this condition, then limited foot traffic creates little damage, if any.

At these times, heavy traffic or golf carts should be restricted from greens, tees and even fairways. This is the most favorable winter conditions, because when the soil is frozen it does not allow as much penetration of compaction and spikes, thus preventing damage to the grass roots. Since the blades are not frozen, they retain the resiliency needed to withstand light foot traffic.

Traffic damage on frozen turf areas usually occurs during periods of freezing or thawing. The most devastating situation occurs when the grass blades and the upper one-half to one inch of soil has thawed, but the ground beneath their level remains frozen. Traffic will create a shearing action of the roots, rhizomes, and crown tissues at this time. This is comparable to cutting the plant tissue from the underlying root system with a sod cutter. Complete kill of leaves, crowns, and rhizomes can occur if the temperatures soon drop below 20° F. Symptoms from this severe injury include whitish to dark brown leaves that may mat on the surface.

Once temperatures allow thawing to a depth of three to four inches, the probability of turf damage declines since about 75 percent of the root system is in the upper four inches of soil. Frequently soil probing is the only positive way to effectively monitor the freezing level. Traffic should be adjusted accordingly.

Many letters and articles are published every year in an attempt to educate golfers to the potential problems of playing on frozen or partially frozen turfgrass areas. Golf course superintendents or club officials should educate golfers in the fall regarding the problems with playing frozen greens so the golfers themselves have a better understanding of the damage that occurs when traffic is imposed on frozen or partially frozen turf. In most cases, informing golfers of suspended play due to frozen greens is inadequate and sounds more like an excuse than a reason. However, if care is taken to educate members through a seminar, newsletter in the golf shop, or a handout distributed directly, it will help members understand exactly what happens when foot traffic is placed on frozen and partially frozen putting surfaces, and it also informs them of winter traffic damage to the turf in general.

If the golf course superintendents and other club officials make a concentrated effort to educate their membership as to why traffic is not allowed on the golf course on particular winter days, they will gain support and will eliminate the current Saturday morning standoffs at the pro shop and the descriptive name-calling sessions which inevitably arise.

Reprinted from the USGA Green Section Record
1984 Sept/Oct Vol 22(5): 8