Owners of blue spruce trees should be on the lookout for a couple diseases that attack the trees’ needles.
Purdue Extension Agricultural Educator Phil Woolery says blue spruces are native to the Rocky Mountain area and are not used to our humidity. “One thing that likes humidity is fungus, and that’s kind of a disease-causing organism for lots of plants,” he explains. “We have a lot of humidity here, so it makes better conditions for fungus. So they don’t know how to deal with some of these diseases as compared to other trees that are used to more humidity.”
He says the diseases will typically infect the needles starting from the lower branches, typically causing them to die within about a year. “I would say it’s very common in our area,” Woolery adds. “Most blue spruces will have some degree of infection. Some will look worse. Some will look better.”
Woolery says there are a few steps you can take to keep the tree healthy. “An easy homeowner fix if you’re starting to see that on the lower branches, you can prune those lower branches off and hopefully slow the spread,” he says. “There are also fungicide treatments available.” He says those treatments should be applied each spring for a few years, to protect the needles from becoming infected. While homeowners can treat small trees themselves, it may take a more expensive professional treatment to properly cover larger ones.
If the situation is bad enough, Woolery says you may consider removing the tree and replacing it with a similar one that does better in the local climate. “Norway spruce won’t have quite that blue color, but it’ll be a similar shape and everything, and it’s not really affected by these diseases at all,” he says. “Another one that I like is white fir or sometimes called concolor fir, and that will have a little more of that blue color to it, too. Those are two kind of similar trees that might work in the landscape similarly.”
Anyone with specific tree questions may call their local Purdue Extension office.
