What does this spring mean for summer turf health?

Not a day went by this spring without a story appearing on local or national news about the rain, storms, or flooding that has rocked much of the United States.  The rain has continued through the early part of the summer causing problems to turfgrass managers across the board. 

Figure 1.  Excessive rain this past spring has resulted in localized flooding and saturated soil conditions.

Daily high temperatures have been for the most part below normal, which combined with the rain has resulted in rapid shoot growth requiring frequent mowing just to keep up.  The difficulty with just keeping up is that the frequent rain delays mowing.  On golf courses, skipping just one green’s mow results in a loss of green speed.  It often takes several days to regain the lost green speed. 

Figure 2.  The excessive rain has resulted in situations where golf courses are closed and athletic fields have postponed games.

Lack of frequent mowing whether on high and short cut turf runs the potential for scalping.  To recover from scalping or excessive defoliation requires the plant to allot additional energy for the recovery.  This spring rapid shoot growth due to relatively cool temperatures and rain has allowed for quick recovering from excessive defoliation to the point it does not seem to be a big concern.  However, repeated scalping going into the summer runs the potential for a depletion in plant energy that can slow plant recovery and predispose it to summertime stresses. 

Figure 3.Too much rain, in some cases, has created some new golf course hazards.

For those golf courses and athletic fields that have undergone repetitive flooding, the turfgrasses have tolerated submersion.  Most turfgrasses whether growing or dormant like bermudagrass are tolerant to submersion under cool water temperatures.  However, with each flooding that has occurred the turfgrass becomes less tolerant to submersion.  Flooding under hot wet summertime conditions could be devastating.

Daily high temperatures, as previously mentioned, have been at or below normal.  However, nighttime temperatures have been relatively warm falling into the high 60s or low 70s.  Given the warm wet nights, we have seen diseases appear that normally do not occur with such frequency.  Anthracnose and brown patch have been prevalent at a time we normally do not see these diseases. 

One positive aspect of all the rain and rapid turfgrass growth it has minimized spring and early summer insect injury.  The turf appears to grow out of any damage caused by the likes of billbugs.  In addition, and it is only an observation, the arrival of the masked chafer and Japanese beetle appears to be delayed at least in Ohio.  

So what does this spring mean for the coming summer? 

Figure 4: When soil temperatures are high (>80 F) and the soil is waterlogged, the potential for wet wilt is creatly increased.

Given the spring, the turfgrass plants have not had a chance to harden-off in anticipation of hot dry conditions.  Dry conditions to the point of wilt or drought in the spring maximize the hardening off process of cool-season turfgrasses.   At this time, the turf is going into summer in a more succulent stage than normal.  The best management practices are to prepare for the worst and then hope for the best.  Start thinking of practices that will minimize summertime stress to the turf.   Listed below are some suggestions for putting green management.  Two major emphases that are touched on are to reduce the potential for wear injury and promote as much air movement as possible.

1. Slightly raising the height of cut to increase wear tolerance and alleviate potential heat buildup
2. Begin some sort of coring practice.  For example, pencil tine or some sort of spiking to alleviate some soil compaction and promote air movement
3. Minimize wear injury.  Practices like reducing the number of cuttings per week by substituting a roll in its place
4. Chronic diseases should be treated preventatively
5. Promote as much air movement as possible across shaded or low lying areas   

Figure 5.  During periods where conditions are favorable for wet wilt, minimize as much stress to the turf as possible.  As one example, reduce the number of mowings per week and supplement rolling to maintain ball roll.  Removing mechanical stress is one part of reducing the level of stress to the turf.