GDD update 8.2.19

Did I fall off the planet?  Just want to get to August before I emailed again?  Nope – 2 programs on greenhouse IPM plus prep and (partial) clean up.


But I’m back now!  Good thing it is a week where there wasn’t much different from last week.


Pennsylvania has a great resource that you can download (or buy a hard copy). Google “Integrated Pest Management for Christmas Tree Production” and look for the pdf version.

Spruce spider mite usually reappears later when it is cooler, but I just learned from my Branching Out that they have been finding populations earlier than expected – so scout for them where you usually see them.

If you have Doug fir, scout for the immature fluffy white Cooley spruce gall adelgid or winged adults coming from the pineapple shaped galls on spruce.  Treat Doug fir at 1500-1775 GDD and blue spruce at 1850-1950 GDD.  And make a note to get the galls off earlier next year!

Thanks, Dawn! (editor of Branching Out)

Here’s how to get your own copy:


Things to do this week:

Elongate hemlock scale – keep scouting for crawlers.

Cooley spruce gall adelgid – prune out galls on spruce before they turn

Cryptomeria scale crawlers – 1750-2130 GDD

Japanese beetle adults – 1029-2154 GDD

Two spotted spider mites– 1300-2000 GDD

Pine needle scale 2nd generation– 1290-1917 GDD