Mr. Arborist why is my Colorado Blue spruce (Picae pungens) turning brown and losing its needles? Take a drive around Newtown, CT and you will easily locate majestic Colorado Blue Spruce trees with their unusual soft blue color. Indeed this blue color is one of the attractive features of this tree and probably the main reason Colorado Blue Spruce are still widely used in landscape setting. Now look closer at the Colorado Blue Spruce and you will begin to observe dead limbs in the lower sections of the crown. In other situations you will see Colorado Blue Spruce with high elevated crowns (in other words the live branches are not continuous to the ground-line). This tree decline is caused by the fungus that attacks Spruce (both Blue Spruce and Norway Spruce) along with Fir and Larch trees. My experience has shown in our area Colorado Blue Spruce is the hardest hit; in fact most Blue Spruce trees begin to show early signs of decline around age fifteen. Cytospora canker according to information from “The Colorado State University Extension Service” is caused by several fungal species of Cytospora (Valsa and lecostoma) and the common name Cytospora canker is derived from the asexual stage of the pathogen that is commonly seen (that being the white oozing sticky sap material found around the dead limbs). Like the other fungi pathogen diseases we have been studying, warm wet springs provide more opportunities for the fungal spores to be released into the atmosphere from their overwintering locations within previously inoculated cankers on branches and stems. Cytospora canker gains entry to unsuspecting Blue Spruce through small existing wounds. Once established in the new host, Cytospora canker grows killing the bark then expands until the entire branch is girdled and expires. I have generally observed Cytospora canker beginning its demise of Blue Spruce from the lower sections of the crown, then continues its assent up until the entire tree is either dead or has lost it aesthetic or cosmetic qualities. There are fungicide treatments, but my experience has shown nothing of good promise worth investing. But cheer up all is not lost as “Paul Harvey” once said,” Let’s hear the rest of the story”. And in the end the best management options is preventive holistic care to alleviate stress on your Blue Spruce. Mulch, Water and fertilization will go far in keeping your prize Blue Spruce healthy and Cytospora canker resistant. If you already have dead lower limbs on your Blue Spruce carefully prune them and dispose of the plant material.
Remember as with any disease or insect problem proper diagnosis is the first order of business prior to any management program. Your Yacko and Sons Tree Service staff Forester will be happy to consult with you on Cytospora canker or any other tree related concern you have. Contact Forester Jeff for your FREE CHECK-UP FROM THE TRUNK-UP and receive your FREE Yacko and Sons Tree Service official green and yellow Frisbee!
