Black Hills Spruce condition

Asked July 4, 2020, 12:26 PM EDT

We have a Black Hills Spruce which was planted a couple of years ago. Some needles, mostly on the north side have turned brown and shriveled up. There seems to be a hard sap like material at the point the needles turn brown.

Dakota County Minnesota

1 Response

Hello. Happy to help.

It may be a symptom of Cytospora canker. I can't say this is definitive from a photo so you may want to consider sending in a sample to the U of MN Extension Plant Disease Clinic for a definitive diagnosis.

I'll attach a link to more information about Cytospora canker but know that you can prune out and destroy infected branches and it can take two years of constant vigilance to reduce this disease. Typically spruces other than the Colorado blue spruce don't get this disease if they are planted in full sun with moist well-drained soil. You say this is occurring on the north side of the tree so I have a feeling that even the early morning and late afternoon sunlight can't reach this area of your tree except for midsummer. But if the early and late light does reach the north side at other times of the year, pruning out problematic branches and twigs should really help.

Here is a link to the PDC where you can learn about their services, prices, and how to submit a sample: https://pdc.umn.edu/

Here is more information about Cytospora canker: https://extension.umn.edu/plant-diseases/cytospora-canker

I hope this information helps.