How do you help a Blue Spruce that has needles that have turned brown and fallen off?


The tops of my Blue Spruce tree turned thin and curly, then brown and the needles have now fallen off.  How do I heal this tree?


Rebecca Long, Sustainable Agriculture and Horticulture Professional

Unfortunately, your spruce has been attacked by White Pine Weevil. This Penn State publication also has good photos. The good news is that this is unlikely to kill your tree and you will just need to do some corrective pruning. You should prune out the dead leader ASAP and destroy it to hopefully also destroy the weevil larvae before the adult has a chance to emerge. From our factsheet:

“At low infestation levels, prompt removal and burning of infested leaders before the weevils emerge reduces the chance of population buildup. Prune infested leaders at a point below the tunneling grubs, at least including some green bark at the base of injury. Immediately burn cut leaders to destroy the larvae and pupae. Wilting leaders may be detected in June and July, but be sure to prune by mid-July to prevent emergence of adults.Pruning infested leaders early in the season before completion of new shoot growth promotes establishment of a new dominant branch and correction of the stem form. Early pruning also prevents the grubs from penetrating the node of the first whorl of branches, reducing the amount of weevil-induced damage.”

Next year you can do corrective pruning to establish a new leader to maintain the shape of your tree:
“Corrective pruning of injured tops should remove all but a single, dominant shoot at the topmost healthy whorl. This promotes healing, resumption of vertical growth and straightening of stem form. Corrective pruning may be postponed until the year after weevil injury to ensure that at least one lateral branch survives ice and snow damage or repeated weevil attacks the following year.”