Sick trees

Asked April 25, 2019, 9:23 PM EDT

I have two conifers that are clearly unhealthy and want to find out what ails them. I've sent in soil samples but do not have results back yet. Qualitatively, soil is very sandy with little organic matter. Other adjacent oaks and pines appear to be healthy.

Grand Traverse County Michigan

1 Response

Looking at your photos my first thought is how much sunlight if the tree receiving? Most conifers like 6-8 hours of sunlight. I believe it is either white or Norway spruce. The branch death looks like it is being caused by Eastern Spruce Gall adelgid.
Eastern spruce gall adelgids are the sap-feeding insects that cause pineapple-shaped galls at the base of new growth. These adelgids overwinter as immature females (stem mothers) in the bark crevices of twigs and around the base of the buds. At this time of the year she will continue to feed and mature. Eventually she will secrete white, wooly wax around her body and deposit eggs. At bud break these eggs hatch into nymphs, which move to the new growth and begin feeding. This feeding causes abnormal twig growth which results in the characteristics galls. The adelgids remain safe in the gall until August/September when the gall turns brown and opens to release mature nymphs. Now is the time to apply an insecticide to control the overwintering stem mother. However, it looks like you have quite a bit of damage and I am not sure you can bring the tree back at this point.

The gray-blue patches on the twigs are lichens. These are interesting organisms, however, do not cause disease problems. They live and gather sunlight on twigs or branches but do not infect the tree. Many lichens grow rapidly when exposed to full sunlight, which explains why we find them on stressed trees.

Please give me a call if you have any other questions.