How Season Changes Affect Turfgrass Management

In North Texas our regional climate change is significantly less than other regions, however, our climate does affect how our turf grasses grow. Turf grass management becomes more in depth as the year progresses, leaving some landscapers scratching their heads. Cooler temperatures usually mean slower top growth and more plant root stimulation. Plants begin to store nutrients for the long dormant period to come. In our region turf grasses slowly go into dormancy caused by a slower than normal cooling period. When it comes to dormancy and temperature, pre-emergent application dates become critical, what time period to apply fall pre-emergent is a matter of debate. Pre-emergent typically are applied after Sept 15th, Consequently, temperature and rate of rain fall play a role as to when to apply fall pre-emergent. Some pre-emergent are post activity pre-emergent, which means they have a longer than average residual, with the ability to kill weed seeds after they have germinated, while other pre-emergent such as pendimethalin must develop a weed barrier over time to prevent weeds seeds from ever germinating in the first place. Nevertheless, a good rule of thumb is to apply pre-emergent after Sept. 15th in this region. Controlling spring weeds is first and foremost the job of a fall pre-emergent, however, some do control winter weeds as they germinate in the fall.