The calls all begin with the saying that they have a spruce, pine, arborvitae or juniper tree that is turning brown.
The next part of the conversation turns to the homeowner asking how they can treat their tree so that they don't lose it. That is when I have to share the bad news about what is killing conifers across Indiana.
Conifers are any gymnosperm tree or shrub that typically bears cones and have evergreen leaves. Pines, arborvitae, and junipers are primary examples of conifers. What many homeowners are finding is that their conifers that have been well-established and growing in a given location for years are suddenly turning brown and losing their needles.
Upon inspection, they do not see any signs of insect or wildlife damage or any disease pathogen present. The next plausible cause is that their beloved conifers have fallen victim to stress.
Conifers that lose their needles or die due to stress are not immediately apparent because of the waxy "coating" found on their needles. Instead, it can take one or two growing seasons after a severe environmental or site stress that has occurred for a conifer to show signs of death. There are several environmental or site stresses that can occur, including excessive moisture, compacted soils, excessive dryness and extreme soil pH.
If an individual thinks back to the past few years, we have experienced several of the environmental or site stresses here in Indiana. Within the last year alone, we have experienced some flooding, a severe drought in the fall, a major ice storm this winter, and then this spring, even more flooding. All of these factors have caused severe stress to occur and impacted conifers across Indiana.
Unfortunately, when the homeowners are contacting the Extension Office, it is too late. They are contacting once the needles have started to turn brown and at that point, nothing much can be done.
To determine if your conifer will produce new growth, check the terminal bud on the branch to see if it is green on the inside. If it is, it is likely to develop in the spring assuming it survives through the winter.
Ultimately, the reasons the conifers are suffering from environmental or site stress is because they generally have shallow roots and prefer fertile, well-drained soil to survive. When we have droughts, their roots are not able to reach the water found deep within the soil, causing the stress to appear.
Likewise, when we have flooding, the roots are saturated with water and often develop root rot diseases.
For more information on conifer dieback, please review the new Purdue Extension publication released by the Purdue Plant and Pest Diagnostic Laboratory, title, "Conifer Dieback." You may obtain your own copy by going to www.ag.purdue.edu/counties/owen/Pages/Fo..., or by contacting your local Purdue Extension Office.
As always, if you have any questions or would like information on any agriculture, horticulture, or natural resource topic, please contact your local Purdue Extension Office at 448-9041 in Clay County or 812-829-5020 in Owen County, or reach me directly via e-mail at firstname.lastname@example.org. Purdue University is an equal opportunity/equal access/affirmative action institution.
Upcoming opportunities available to you through Purdue Extension include:
* Saturday -- Discovering Your Watershed: Griffy Lake (Educational Canoe Trip), Bloomington. Cost is $12,
* June 28 -- Clay County Extension Homemaker's Achievement Program,
* June 28 -- Clay County Extension Board Meeting, 7:30 p.m., Extension Office, and
* June 29 -- Owen County Extension Homemaker's Achievement Program.