Tree Talk: What’s bugging your trees

Aaron Kiesz Aberdeen Parks
Recreation and Forestry Department

June is a month where we see various insects and diseases affecting all kinds of trees. This year, Cedar apple rust has been very prevalent on Junipers. This disease shows up as bright orange “globs.” These globs will release spores that cause spots to appear on apple leaves later in the season. This disease is not usually serious, although some leaf drop may occur, so treatment is not normally recommended. Junipers are even less affected by this disease.

Cottony maple scale is also starting to show up. The presence of little brown scales on the surface of branches with a white puff of cotton is a sure sign of this insect. These insects will feed on the tree, releasing honeydew, a sappy substance that rains down from the trees. There are a few controls available, but again, we normally don’t recommend any as nature will take its course. My best recommendation is to pick something other than a maple when heading out to plant a tree.

Yellowing maples is a common sight in Aberdeen. These yellow leafed trees are slowing dying from a micro-nutrient deficiency, and there is no cure. Treating with chelated iron can sometimes help green the tree up, but it will be a yearly maintenance process.

Dying Spruce trees are by far my most common call. Spruce, specifically Colorado Blue Sprucem are affected by numerous insect, disease and environmental problems. Again, if you are going out to plant a spruce tree, plant a Black Hills Spruce or the newer introduced variety, Meyer Spruce.

Many of the problems trees develop are because they are under stress. It doesn’t always have to be moisture stress, but this year that appears like it will be a contributing factor. So make sure to water your trees!

Aaron Kiesz is the city forester for the Aberdeen Parks, Recreation and Forestry Department. Contact him for additional information or questions at or 605-626-7015.

Aaron Kiesz, Aberdeen Parks, Recreation and Forestry Department