I often receive emails and phone calls with regard to pine and spruce decline--these inquiries come from southern, central, and northern Illinois.
Even though Illinois is home to eight native conifer species, many conifers are planted on sites/soils that do not encourage long-term tree health and vigor. Many conifers adapted to Illinois's climate require well-drained soils and unfortunately, many of these trees are planted on fine-textured, poorly drained to somewhat poorly drained soils. Inevitably, complications result and we refer to these complications as "decline" -- environmental conditions that cause tree health and vigor problems.
If you suspect wide-scale conifer decline, please contact your local Illinois Dept. of Natural Resources district forester office: