1. Educational Information: Growing Degree Days (GDD)
What is GDD?
GDD is a crucial metric in understanding the growth patterns of plants, including turf grass, and is invaluable for optimizing maintenance strategies and predicting developmental stages. GDD measures the accumulation of heat over a specified threshold temperature, typically between 0°C and 30°C (32°F to 86°F), which is the range most relevant to processes such as seed germination, plant growth, and pest development.
How is GDD Calculated?
GDD=(MaxTemp+MinTemp)/2−BaseTemp
Negative values are truncated to zero.
Typical temperature range: 32°F–86°F (0°C–30°C).
2. Accessing the GDD Trackers
To create, pause, restart, or archive GDD trackers:
Open the GreenCast Connect app
Navigate to Settings (tap the gear icon ⚙️)
Select GDD Trackers
From this page, you can view active and archived trackers, as well as create new ones.
When creating a new tracker, you will be asked to define:
Tracker Name
Tracker Type (e.g., turf or pest)
Threshold Type (e.g., accumulated GDD or calendar days)
Threshold
Base Temperature
Start Date
Selected Target Species
Once a tracker is created, it can then be added to your Dashboard as a widget.
3. Adding GDD Trackers to Your Dashboard
After creating a GDD tracker in Settings > GDD Trackers, you can add it to your Dashboard.
To add a GDD Tracker widget:
Navigate to the Dashboard
Tap the plus sign (+) in the top-right corner
Tap the plus sign (+) again from the Organize Dashboard page
Locate and select your GDD Tracker widget
Return to the Dashboard to view it
Note: GDD trackers must be created in Settings > GDD Trackers before they can be added to the Dashboard.
4. Viewing GDD Data
Once your GDD Tracker widgets have been added to the Dashboard, they will display current accumulated GDD values for each tracker.
Important Notes:
GDD Tracker widgets in the app show current and ongoing data only and do not include long-term historical graphs
For more detailed or long-term GDD analysis, use the desktop version of GreenCast Connect at app.greencastconnect.com
You may see some GDD-related activity reflected in the Diary, such as alerts or threshold events associated with your trackers
GDD-related activity (including Diary entries) is only recorded from the time the tracker is created and active
Historical GDD data is not backfilled, meaning the Diary will not populate past GDD events prior to the tracker being set up
Active and Archived GDD Trackers
Active and archived trackers will display on your dashboard.
Ability to pause, restart, or archive the GDD tracker as needed by selecting it in the dashboard or under Settings-GDD Trackers.
Once a tracker is created, you can only edit the threshold days.
Edit the GDD threshold directly within the tracker settings for more accurate monitoring.
You cannot edit any other aspects of the tracker once it is created, but you can create a new tracker with updated settings if needed.
Note: once a GDD tracker is archived it cannot be undone.
Applications of GDD Trackers
GDD values can enhance turf-grass management strategies:
PGR Timing:
Plan plant growth regulator reapplications based on accumulated GDD.
Application Frequency:
Determine optimal timing for treatments by tracking GDD since the last application.
Pest and Disease Management:
Monitor pests with specific GDD thresholds for development and activity.
Tips:
Set Accurate Base Temperatures: Ensure base temperatures match the specific needs of your turf-grass or target pests.
Use Multiple Trackers: Add GDD trackers for different species or management goals.
Monitor Regularly: Review active GDD trackers to adjust your maintenance strategies as conditions change.