This information will be updated weekly from March through October to provide current data for use in making pest management decisions. The accumulated Growing Degree Days are 121 from March 1, to March 25, 2020.
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:
A crop will reach maturity.
An insect will emerge from dormancy
The date a flower will bloom
By monitoring the GDD on a daily or weekly basis it is possible to respond accordingly with timely controls.
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
How to Use the Following Table
Using the following table will improve the timing of control measures by helping predict when common pest will appear in Chesterfield County. The table uses the minimum GDD, from past years, to show how it is helpful to monitor pests on a daily or weekly basis in order to predict the appearance and respond accordingly.