Normally there would be a fear of jinxing myself with a statement like that. In this case however, I am not worried about getting hit with a series of bad snow storms all of the sudden. It appears as though Old Man Winter has decided to follow up two of the worst winters on record, with one that may end up being the mildest on record in the last sixty years. As I stated before, that is great news for the membership here at Springhaven.
What has yet to be seen though, is how this will affect things scientifically. There have already been reports across lower portions of PA that are seeing patterns associated with mid to late March weather in late February. Forsythia’s have begun blooming in some areas, daffodil’s are already a few inches tall, and migratory birds have been seen flying north. These occurrences are generally labeled as phenological indicators, and are a basic way of determining when spring is about to start. We also use phenological indicators and growing degree days (GDD) as a strategy for timing chemical applications, cultural practices, and general golf course prep work. For example, forsythia can begin blooming at 1-27 GDD while a threatening insect like the annual bluegrass weevil (ABW) can become dangerously active at 100-120 GDD.
SO WHY AM I TALKING ABOUT THIS?
In a normal year, we begin our GDD monitoring on March 1st. We generally have very good success when doing so, and are able to use phenological indicators as a way to double check the accuracy of our GDD tables. For example, forsythia’s are generally 50% green and 50% yellow after about 100 GDD. Knowing that ABW adults begin feeding at around 100 -120 GDD, we monitor forsythia bloom for insecticide timing. With this winter being so mild, and the phenological indicators already present, our GDD models may or may not be helpful this year. Fortunately, we are aware of the possible inconsistencies with nature and have already begun a strategy for our spring work load. We will monitor GDD as we do every year, as well as incorporate other techniques we have learned throughout our careers.
Please visit the greens department website for a great “Thru The Green” article on Poa seedheads. It was written by Charlie Miller and is titled April ’09 – Seedhead Suppression.
Quick List of Phenological Indicators:
Forsythia’s bloom, daffodil’s emerge, magnolia trees begin to bud out, Spring Peeper frog becomes noisy, Spring Azure butterfly can be seen in wooded areas, geese fly north, and the ever so popular…the sightings of the Robin.