Why do Bentgrass greens, particularly those at Highlands CC, turn patchy colors this time of year?
Our putting greens were established in 1999 with a variety of Bentgrass called, Penn A4. This turf was developed by a plant breeder at Penn State University named Dr. Joe Duich. Dr. Duich is widely know as the “Godfather” of Bentgrass varieties since he developed Penncross, back in the late 1950s. All newer Penn varieties of Bentgrass are mutations of this original variety, Penncross. The A and G series of Penn bentgrasses were selected off the par 3 course greens at Augusta National GC. Again, those greens were originally seeded with Penncross. Over time, plants will mutate and other biotypes and segregations will develop. In many cases, the grasses can even revert back to their original parent material. Penncross was a cross pollination of 3 different varieties of Bentgrass. One of the three was known as PennLu Bentgrass. This variety was infamous for turning purple once it was exposed to freezing temperatures. That’s what you’re seeing on our greens. The Penn A4 is showing its parent varieties in the Penncross and ultimately PennLu Bentgrass. Next time you’re on the greens, check out all the different segregations- some patches are different shades of green while others are very dense. Some even have resistance to certain fungal diseases. When you look at a putting green a little deeper with a different perspective, it’s fascinating what you can learn!