Good morning:
I contacted the University of Minnesota Extension Master Gardener volunteer program in late January when we noticed damage to th...
Knowledgebase
NEEDLECAST IN SPRUCE TREES #867207
Asked May 06, 2024, 11:12 AM EDT
Good morning:
I contacted the University of Minnesota Extension Master Gardener volunteer program in late January when we noticed damage to three of our mature spruce trees that had browning of the needles at the center of the tree. We sent pictures and a Master Gardner called and confirmed that it was in fact needle cast.
We trimmed the bottom branches which were heavily damaged, removed the diseased branches and other shed from the surrounding area and did further research which recommended a couple of fungicides for needle cast but found that in looking at the trees more in-depth that the needle cast seems to have progressed almost to the tops of the trees which we believe are over 25 feet tall.
My husband called the Extension Service<personal data hidden>) February 12, 2024 and left a voice mail message requesting a return call and inquiring whether we had any hope for the trees if we sprayed a fungicide; or if we should keep watering the roots, mulch and pray for the best. We have not received a return call to this date.
The purpose of this email is to ask a couple of questions:
whether we should purchase a fungicide and spray the trees, if so, are there any that the U recommends?
Is there any hope, or should we water, mulch and hope for the best?
I have attached two pictures for your review and consideration. Thanks for your help and assistance. We appreciate your program!
Sincerely,
Lois Durenberger
31415 Marvin Ave
Lindstrom, MN 55045
Hennepin CountyMinnesota
Expert Response
Fungicidal applications for needle cast can be effective but timing is everything and proper diagnosis is necessary.
To properly diagnose needle cast in spruce you should submit a sample for examination under a microscope. You can send your sample to the Plant Disease Clinic at the link below. You can call them first for specific instructions on how to collect and submit the sample.
Trees that are under stress are moser susceptible to needle cast. We have had 3 years of drought, so water you choose to do, keep them well watered. Even mature trees are suffering right now. But - water at the base and do not let sprinklers spray the needles.
It is also good that you have been cleaning up the debris beneath them. Because of their size, you may want to hire a tree service to spray the fungicide.
Be sure to talk with them about timing. Spraying at the wrong time will not be effective. Now is the time to get on this.
Good luck - from the photos they are still beautiful trees.