Growing Degree Days
This information is updated weekly from March 2022 through October 2022 to provide current data for use in making pest management decisions.
The accumulated Growing Degree Days value from June 17, 2022 to June 22, 2022 is:
1567.5
About Growing Degree Days (GDD)
The GDD are a measure of heat accumulation used by horticulturists, gardeners, and farmers to predict plant and animal development rates. For example:
- Determine stage of crop development and maturity
- Predict insect emergence from dormancy and developmental life stage
- Estimate plant development and reproduction
By monitoring the GDD on a daily or weekly basis it is possible to make accurate and timely decisions to protect and enhance your crop or plants.
Growing Degree Day values for various insects
| Pest | Minimum GDD |
|---|---|
| Eastern Tent Caterpillar | 92 |
| Pine Tip Moth | 121 |
| Pine Spittlebug | 148 |
| Azalea Lace Bug | 239 |
| Two-spotted Spider Mite | 363 |
| Euonymus Scale | 406 |
| Boxwood Leaf Miner | 448 |
| Bagworm | 600 |
| Fall Webworm |
867 |
| Japanese Beetle |
970 |
How It’s Calculated
Calculating GDD is determined by the difference between the daily average air temperature and the base temperature of 50 degrees Fahrenheit (10 degrees Celsius). You must first find the mean temperature for the day. The mean temperature is found by adding together the high and low temperature for the day and dividing by two:
- Max Temperature plus Minimum Temperature divided by 2 minus Base Temperature equals the Daily GDD