This summer has been slightly challenging due to the lack of rain. On top of that, we have a stiff breeze and high skies each day. When grass (or any plant) doesn't have any available water, it will wilt. This is the plant's way of conserving water. It realizes it can do what it needs to do so it shrivels up, gets "crispy" and turns purple. The next day, it's brown. So what exactly happens? A plant is constantly taking water up by way of roots and at the same time, releasing water into the atmosphere though the stomata (microscopic holes in the leaves). This is how it cools itself off- evaporative cooling- the same reason you feel cold when you step out of the shower. This process is called transpiration, the same basic process as a human sweating. The total amount of water lost in the soil whether it be by direct evaporation or plants transpiration is known as evapotranspiration. In fact, our goal for irrigation is to replenish the quantitative amount of evapotranspiration... Pretty simple concept.
When a plant is trying to cool itself off on a hot day but the roots have no available water, It wilts. In most grass species this triggers dormancy. Simply put, the grass says, there is no water for me so I'm going to shut down and when the water returns, I'll wake up. This is very similar to what warm season grasses do in the winter. Poa annua on the other hand, has no dormancy trigger. When Poa annua wilts, it is dead. This is one reason bentgrass on often times a more desirable grass. In the rough, Kentucky Bluegrass is far more heat and drought tolerant than bentgrass. Again, a reason why the KBG is more desirable in roughs. Fine fescues are the most drought tolerant turf species.
On cool season turf, wilt is a natural process and one you can expect on fairways and roughs. There is no way to maintain firm fairways during weather like this and have lush green growth. The word lush alone is associated with excess water and nutrients. If the course was green wall to wall, we would be sopping wet and the course wouldn't play as well. Just know that the few little brown spots will go away once the rain starts back up. This is Highlands and it's a matter of time!
