Plant Phenology

Here is your Growing Degree Day (GDD) summary ending June 30, 2023. This summary is a year-to-date summary and includes the months of January, February, March, April, May and June.

Here is your Growing Degree Day (GDD) summary ending March 31, 2023. This summary is a year-to-date summary and includes the months of January, February and March. Stay tuned for these year-to-date summaries each month in 2023.

Here is your Growing Degree Day (GDD) summary ending March 31, 2023. This summary is a year-to-date summary and includes the months of January, February and March. Stay tuned for these year-to-date summaries each month in 2023. 

Here is your Growing Degree Day (GDD) summary ending February 28, 2023. This summary is a year to date summary and includes the months of January and February. Stay tuned for these year-to-date summaries each month in 2023.

Here is your Growing Degree Day (GDD) summary ending June 30, 2022. As we turn the page into a new month, the information will be compiled from the months previous. And as always, you can monitor the site more regularly, and compare years by using the summary icon on the webpage.

Years ago, a Growing Degree Day (GDD) article was a reoccuring staple in what was the weekly Buckeye Yard and Garden Line (BYGL) e-newsletter. While the newsletter evolved into a real time, blog-like, format, GDD information still had a presence as an occasional summary, and of course was included in many of the insect alerts. In 2022, you will be seeing monthly summaries, and we will continue to tie in GDDs into other alerts as well.

So what is your GDD - or growing degree day? Before you reach for a piece a paper, a pencil and a calculator to figure out what your number is, check out the OSU's Growing Degree Day website. This website does the 'math' or the calculations to determine your GDD for you. All you need is an Ohio zipcode. The website uses weather stations across Ohio to determine what the accumulations, and provides visitors their GDD and where they are in a biological calendar of certain plant blooms and insect activity. 

Growing Degree Days (GDD) are a measurement of the growth and development of plants and insects during the growing season. Development does not occur at this time unless the temperature is above a minimum threshold value, or what is also referred to as the base temperature. This base temperature can vary for different organisms and is determined through research and experimentation.

Last month, a BYGL Alert was written as an intro or refresher to growing degree days followed by a second alert, Growing Degree Days (GDD) – Part 2, (March 16, 2020), https://bygl.osu.edu/index.php/node/1455 . And ealier this week, Joe Boggs authored a BYGL Alert, Observations on Phenology (April 13, 2020), https://bygl.osu.edu/node/1504 highlighting the sequence of plant bloom, insect activity and optimal timing for pest management. 

Amy Stone (OSU Extension, Lucas County) posted an informative BYGL Alert earlier this season on Growing Degree Days (GDDs) [click this hotlink: https://bygl.osu.edu/node/1448 ]. She highlighted and described our Ohio State Phenology Calendar that was developed by Dan Herms (Davey Tree) and during his time with us at OSU [click this hotlink: https://www.oardc.ohio-state.edu/gdd/default.asp ].