What’s Wrong with my Blue Spruce?

Has your Colorado Blue Spruce been turning a purplish brown color and losing needles? If so, it could be infected with needlecast. Needlecast has become such a problem lately that Purdue University has issued a landscape report on the disease. No need to fear: the effects of needlecast can be reversed if the disease is caught early enough and other alternatives are available to replace your spruce.

What is Needlecast?

Needlecast is a fungal disease caused by the fungus Rizosphaera kalkhoffii. Because the Colorado Blue Spruce is not a native of Indiana, it makes it particularly susceptible to disease. Indiana’s humid climate provides the perfect environment for needlecast to thrive. The fungus will remain in the needles of the spruce over winter and develop as soon as temperatures begin to rise. Without proper treatment, needlecast can cause irreversible defoliation and the eventual death of the tree.

Symptoms of Needlecast in Blue Spruces

Symptoms of needlecast can take two to three years to develop after the initial infection. Common symptoms to look out for include:

• • • Purplish brown needles that fall from the tree, beginning at the bottom of the tree and working up. (Note: higher portions of the tree can still become infected at any time).

       

    • Rows of small brown/black dots along the length of the needles of the tree. These dots are “pycnidia” – the spores of needlecast.

Treatment or Replacement?

The Colorado Blue Spruce is extremely susceptible to needlecast. The best solution for avoiding the disease is to plant other varieties of spruce.

If your spruce is already affected, you have two options depending on the level of damage present. If the damage is light, try to treat the tree in the spring. Fungicides, particularly those that are copper based, can be effective in treating needlecast. If the damage to the tree is severe, it is better to remove the tree and replace it with a different variety of spruce that is less susceptible to the disease. The best option would be to install a Norway Spruce instead.

Think your tree may need to be replaced? We can help! Check out our tree removal and replacement services.