Norway spruce top brown

Asked July 3, 2018, 1:48 PM EDT

Hello, We planted a norway spruce about 3 years ago. At 1st year, it was rough but it has been growning well. Now it almost 12 ft. However, it turned brown at the top of the main trunk 2 weeks ago and it seems going down. I don’y know what causing issue. The lawn weed killer can damage it? Please letme know if you have any thoughts and what to do. Guve your expertise. Thanks. Attached the pic.

Oakland County Michigan

2 Responses

I suspect the damage to the leader is caused by white pine weevil. White pine weevil larvae kill the terminal leader on many varieties of spruce, as well as white and Scots pine trees. Damage from white pine weevil can be distinguished from other types of injury by the somewhat curled shape of the leader, sometimes referred to as a “shepherd’s crook”. If you examine the leader, there are numerous small holes in the bark and leaking sap or pitch will drip down the leader from the holes. When bark is peeled off the dying leader, slightly curved, white larvae are found under the bark. These leaders should be pruned out when the first symptoms appear. Cut the terminal leader off an inch or two below the area damaged by the weevils. After the dead leader is removed, select a healthy lateral shoot on the uppermost whorl to become the new leader. Trim the rest of the shoots back to one-half of their original length. This will enable the tree to recover its apical dominance and good form faster. Damage from white pine weevil can be prevented by spraying the upper terminals of spruce and pine next year in early to mid-April and again two weeks later. Identifying damage - http://msue.anr.msu.edu/news/white_pine_weevil_damage_on_conifers_is_causing_wilted_leaders Controlling white pine weevil - http://msue.anr.msu.edu/news/control_white_pine_weevil_in_early_spring

Thanks for giving your expertise.
When I peeled off the dying leader, I was able to see the larvae and leaking sap!!

I will keep to monitor how it goes well, since I cut it out.

Again. Thank you for root causing.
Jay