I love this picture for a number of reasons. On the right, you can see the definitive line of fresh Kentucky Bluegrass sodded around the #6 green side bunker this winter. Left of that is the 'mountain mix' of rough grasses you find on the golf course. Many wonder why can't we keep straight Kentucky Bluegrass (KBG) in all areas?
Our rough consists of 4 types of grasses in the rough. They are: KBG, Poa annua, bentgrass and ryegrass. Over 80 plus years of HCC, all sorts of genetic mutations have taken place and ultimately survival of the fittest determines which species is dominant. However, it is this time of year (spring) where we lose a lot of ground. The species of turf start growing in this order:
1. Poa annua
2. Creeping bent
3. Per. Rye
4. KBG
What this means, is Poa annua grows at a much cooler temperature than KBG. During this month or two, these less desirable species had a great competitive advantage over the desired, KBG. This is one reason of many the Poa annua does so well in our climate. KBG isn't very active until we hit temperatures near 80*. Poa annua on the other hand, is actively growing at temperatures in the 50's. In fact, if our greens were Poa annua, I would venture to guess we would already be healed from aerification. The new varieties of bentgrasses require more heat as well compared to the old school, Penncross variety.