Spruce Spring Dormant OIl spray

Asked April 21, 2019, 4:28 PM EDT

the MSU Ag web site says the time to spray for Cooley and Eastern spruce gall adelgids is 25 to 120 GDD50..Could you put this in a more user/layman freindly terms. My "tree guy says the 1st three days of 75 degree weather. I live on Grand Traverse Bay in Lelenaw county

Grand Traverse County Michigan trees and shrubs insect issues evergreens conifers

1 Response

Hi. The area you live in has accumulated about 52 degree days (base 50) thus far this year. The projected degree day accumulation is about 60 by the end of the week. You can find data like this yourself at the MSU Enviroweather web site:
https://enviroweather.msu.edu/weather.php?commodity=&stn=nwm