There are several reasons why Poa has to be watched closely, and one of the key factors is the root system...or lack thereof. When compared to Creeping Bentgrass, Poa has a fraction of the roots.
Last week, we had days with evapotranspiration rates of .25-.30". That's a lot of moisture being lost, and Poa's short root system limits the area from which the plant can draw water to replace what it's using.
|The Poa sample at the top has approximately 1/2 the root length of the Bentgrass sample beneath.|