Diplodia Shoot Blight and Canker

Diplodia shoot blight and canker is one of the most common fungal diseases of Austrian pine in Wisconsin. This disease can also affect other pines including red, jack, Scots and mugo pine, as well as other conifers including cedars, cypresses, firs, junipers and spruces.

Ips Bark Beetle

Ips bark beetle, also known as the pine engraver, is an insect that attacks and kills weak, stressed, declining and dying pine and spruce trees. These insects are attracted to trees that have been stressed from drought, construction damage, overcrowding, transplant shock, flooding, disease and other insect problems. Identification and management are covered in this fact sheet.

Dothistroma Needle Blight

Jim Olis* and Brian Hudelson, UW-Madison Plant Pathology *Completed as partial fulfillment of the requirements for a BS in Plant Pathology at the University of Wisconsin Madison. Revised:  8/6/2012 Item number:  XHT1078 What is Dothistroma needle blight? Dothistroma needle blight is a common needle disease that can affect over thirty species of pine trees.  In […]

Swiss Needle Cast

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1148 What is Swiss needle cast?  Swiss needle cast is a fungal disease of Douglas-fir.  This tree is native to the Rocky Mountains and the Pacific Coast, but has traditionally been grown in Wisconsin as a landscape ornamental and as a Christmas tree.  […]

Weir’s Cushion Rust of Spruces

Glen R. Stanosz, UW Madison Plant Pathology, and Forest Ecology and Management Revised:  8/13/2012 Item number:  XHT1119 What is Weir’s cushion rust? Weir’s cushion rust is a needle disease that disfigures and reduces growth of spruce trees (Picea spp.) of all ages.  This disease has been known in both eastern and western regions of the […]

Armillaria Root Disease

Michael Amman, UW-Madison Forest Ecology and Management and Glen R. Stanosz, Ph. D., UW-Madison Plant Pathology Revised:  8/6/2012 Item number:  XHT1120 What is Armillaria root disease?  Armillaria root disease, also known as shoestring root rot, is an often lethal disease of tree and shrub roots and lower stems.  It can affect almost any conifer or […]

Phytophthora Root Rot of Christmas Trees

Phytophthora root rot is a common disease of Christmas trees including Douglas-fir, balsam and true firs (e.g., Fraser, balsam and Canaan), spruces, and pines. This fact sheet covers symptoms and management.

Western Conifer Seed Bug

Phil Pellitteri, UW Insect Diagnostic Lab Revised:  4/27/2004 Item number:  XHT1052 Western conifer seed bugs belong to the leaf-footed bug family Coreiidae.  Adults are 3∕4 of an inch long, elongate, reddish to dull brown with a faint, white zigzag straight line across the center of the wings.  They have long, thin antennae and hind legs […]

Gymnosporangium Rusts

Authors: Brian Hudelson, UW-Madison Plant Pathology Last Revised: 01/23/2019 X-number: XHT1009 What are Gymnosporangium rusts? Gymnosporangium rusts are a group of closely related diseases caused by fungi that infect both junipers (in particular red cedar) and woody plants in the rose family (such as, but not limited to, apple, crabapple, hawthorn and quince). These fungi […]

White Grubs on Christmas Trees

P.J. Liesch and R. Chris Williamson, UW-Entomology Revised:  5/20/2013 Item number:  XHT1208 White grubs (i.e., larvae) of the common May/June beetle or “Junebug” (Phyllophaga spp.) are an important pest of Christmas trees in Wisconsin.  This soil-dwelling pest feeds on the roots of pines, firs, and spruces, and can cause damage severe enough to kill small […]

Pruning Evergreens

Pruning is important for a variety of reasons. Pruning can help control the size of an evergreen, direct growth, or maintain plant health and appearance. Pruning can also increase the safety of an evergreen by removing broken, diseased, dead, or dying branches.

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