Downy Mildew

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:  XHT1077 What is downy mildew? The downy mildews are a group of fungal diseases that cause destruction of the leaves, stems, flowers and fruits […]

Apple Scab

Brian Hudelson, UW-Madison Plant Pathology Revised:  11/19/2018 Item number:  XHT1007 What is apple scab?  Apple scab is a potentially serious fungal disease of ornamental and fruit trees in the rose family.  Trees that are most commonly and severely affected include crabapple, hawthorn, mountain-ash, apple and pear.  In ornamental trees, leaf loss caused by apple scab […]

Plants Not Favored by Deer

If deer visit your property, you’ve likely already experienced the frustration of having landscape plants destroyed overnight. Before planting (or replanting), check out this list of trees, shrubs, flowers, herbs, and grasses that deer tend to avoid.

Root and Crown Rots

Brian Hudelson, UW-Madison Plant Pathology and Laura Jull, UW-Madison Horticulture Revised:  8/13/2012 Item number:  XHT1070 What is root/crown rot? Root/crown rot is a general term that describes any disease of woody ornamentals where the pathogen (causal organism) attacks and leads to the deterioration of a plant’s root system and/or lower trunk or branches near the […]

Herbicide Damage

Brian Hudelson, UW-Madison Plant Pathology Revised:  5/11/2010 Item number:  XHT1004 What is herbicide damage?  Herbicide damage is any adverse, undesired effect on a plant that is caused by exposure of that plant to a pesticide designed for weed control (i.e., a herbicide).  Any plant can be subject to this problem.   What does herbicide damage […]

Gray Mold (Botrytis Blight)

Jeffory Schraufnagel*, Milwaukee Area Technical College, Brian Hudelson, UW-Madison Plant Pathology Revised:  5/11/2010 Item number:  XHT1122 What is gray mold?  Gray mold (or Botrytis blight) is a common and often serious fungal disease that can affect plants of all kinds.  Gray mold is a particularly serious problem on flowering plants and those plants grown in […]

Spongy Moth

P.J. Liesch, UW Entomology and R. Chris Williamson, formerly UW Entomology Revised:  4/1/2022 Item number:  XHT1063 The spongy moth, Lymantria dispar (formerly known as the “gypsy moth”) is native to parts of Europe, Asia, and North Africa. It was inadvertently introduced to North America in New England in 1869 and has since spread westward. Over […]

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 […]

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.  […]

Bacterial Blight

Gina Foreman* and Brian Hudelson, UW-Madison Plant Pathology *Completed as partial fulfillment of the requirements for Plant Pathology 875 – Plant Disease Diagnostics Clinic Internship at the University of Wisconsin Madison. Revised:  4/25/2004 Item number:  XHT1093 What is bacterial blight?  Bacterial blight, also known as blossom blight or shoot blight, is a common and often […]

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 […]

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