Guignardia Leaf Spot

Brian Hudelson, UW-Madison Plant Pathology, UW-Extension Revised:  4/28/2012 Item number:  XHT1123 What is Guignardia leaf spot?  Guignardia leaf spot is a common fungal leaf spot that affects vining plants such as Boston ivy and Virginia-creeper.  The pathogen that causes Guignardia leaf spot also causes a leaf spot and fruit rot of grape called black rot. […]

Golden Canker (Cryptodiaporthe Canker)

Brian Hudelson, UW-Madison Plant Pathology, UW-Extension Revised:  8/6/2012 Item number:  XHT1125 What is golden canker? Golden canker (officially Cryptodiaporthe canker) is a visually distinct and increasingly common disease of alternate-leafed dogwoods such as pagoda dogwood. This disease can potentially be lethal if infections occur on the main trunk of a tree. What does golden canker […]

Euonymus Scale

Phil Pellitteri, UW Insect Diagnostic Lab, UW-Extension Revised:  8/6/2012 Item number:  XHT1153 Euonymus scale is a non-native scale that attacks evergreen shrub and vine forms of Euonymus (e.g., wintercreeper).  In addition, this insect attacks privet, bittersweet and pachysandra. Appearance: Euonymus scale females grow up to 1/16 inch in length, are brown and are shaped like […]

Dutch Elm Disease

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:  XHT1076 What is Dutch elm disease? Dutch elm disease is a lethal fungal disease of native North American elms.  The fungi that cause Dutch […]

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 […]

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.

Deciduous Tree Galls

R. Chris Williamson, UW Turf and Ornamental Specialist, UW-Extension Revised:  8/6/2012 Item number:  XHT1024 Galls are abnormal growths on plants that can result from the feeding of living organisms such as bacteria, fungi, nematodes, insects and mites.  There are numerous galls that are caused by insects, the most common of which, in Wisconsin, are ash […]

Cytospora Canker

Brian Hudelson, UW-Madison Plant Pathology, UW-Extension Revised:  3/11/2012 Item number:  XHT1003 What is Cytospora canker?  Cytospora canker is one of the most common fungal diseases of Colorado blue spruce.  This disease can also affect Norway spruce (and less frequently other spruces) as well as Douglas-fir and balsam fir.  Trees that are 15 years old or […]

Chlorosis

Brian Hudelson, UW-Madison Plant Pathology, UW-Extension Revised:  1/8/2012 Item number:  XHT1002 What is chlorosis?  Chlorosis is a common nutritional disorder of many woody ornamentals in Wisconsin, particularly in the southern and eastern parts of the state.  Pin oaks are most commonly affected by chlorosis, although many other trees and shrubs (e.g., white oak, red maple, […]

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 […]

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.

Home Landscape Insecticides

Karen Delahaut, UW-Madison Fresh Market Vegetable Program Revised:  8/13/2012 Item number:  XHT1096 Recently, several commonly-used insecticides for the control of insects on woody landscape plants have been taken off the market.  As a result, it’s becoming ever more challenging for home gardeners to find suitable insecticide products at garden centers, discount stores, and hardware stores.  […]

Support Extension