Resource of the Week: Growing Degree Day (GDD) Tracker
Growing Degree Day Tracker at www.gddtracker.net
If you live in Illinois, Indiana, Michigan, or Ohio, this tool is essential. Developed by the good people at Michigan State University and further supported by the Turf Foundations of surrounding states, it is completely free to use. The Growing Degree Day (GDD) Tracker monitors and displays GDD information by specific geographical area, allowing you to more accurately time your product applications to your turf.
To use, simply go to www.gddtracker.net and submit your zip code. You will see a map of the Midwest. Your location will be marked with a star. Each dot on the map represents a station where temperatures are recorded and submitted for use on the site. Now begin to select the different categories to the right. Colors on the map will correspond to the colors on the chart below. Play around with the different categories and discover the wealth of information you can gain from this one site.
If some of the categories seem confusing to you or irrelevant, that’s likely because this was developed primarily for those in the golf course industry where these categories are very important. Even if you don’t ever think about Bluegrass Billbugs or Annual bluegrass seed-head suppression, the Crabgrass pre-emergent and spring broadleaf control timing are worth keeping this site bookmarked.
If you have questions about the different categories, select the ‘About’ tab at the top of the page. The site will go into detail about each category.
What is a Growing Degree Day?
A Growing Degree Day is a mathematical measurement of the collective temperatures for a season in a particular area. I don’t get excited about the math, but if that’s your cup of tea check out Purdue’s explanation or the University of Illinois’. This measurement has been critical in agriculture to understand the timing of plant growth, insect emergence, and planning of chemical applications.
Why is this important? Look at the back of your bag of crabgrass pre-emergent. It likely has a map with a recommended range of dates for application. Well, what if we have an unseasonably warm winter and early spring (sound familiar?)? How does that impact the timing of that material? Missing your application window wastes material and time and you can’t afford either. The GDD Tracker has you covered, measuring real temperatures and calculating real GDD.
One of the best features of this site is your ability to receive customized email alters. Want to know when it’s time to spray for spring broadleaf weeds? GDD Tracker will email you when your area is ready. A few really warm days in a row can really move the growing season along quickly. Getting an email alert helps ensure you don’t miss your application window.
Let the GDD Tracker team know what you think by sendnig feedback. To support their work, spend a few dollars on this great poster. It’s a great visual to help your team identify common turf weeds and better understand when to expect them to appear. I’ve hung one up in my shop in the past and it becomes a teaching tool and conversation piece every spring.
While you are on the GDD Tracker page, click on the link in the upper right-hand corner for more resources from the MSU Extension office.