Elderberry Rust

Elderberry rust is a visually striking fungal disease that affects stems, leaves and flowers of plants in the genus Sambucus (i.e., elderberries). The disease also affects sedges (Carex spp.). On elderberries grown as ornamentals, as well as on sedges, the disease is primarily a cosmetic problem.

White Pine Blister Rust

Joseph Schwartz, UW-Madison Forest Ecology and Management and Glen R. Stanosz, Ph. D., UW Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1118 What is white pine blister rust? White pine blister rust is a serious, tree-killing disease of eastern white pine and its close relatives (pines with needles in bundles of five).  This disease is […]

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 […]

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 […]

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, […]

Root Rots in the Garden

Brian Hudelson, UW-Madison Plant Pathology and Laura Jull, UW-Madison Horticulture Revised:  5/20/2011 Item number:  XHT1072 What is root rot? Root rot is a general term that describes any disease where the pathogen (causal organism) attacks and leads to the deterioration of a plant’s root system.  Most plants are susceptible to root rots, including both woody […]

Eastern Filbert Blight

Eastern filbert blight is a potentially serious fungal disease found throughout the United States, including Wisconsin. It affects Corylus species, commonly known as hazelnuts or filberts, causing cankers on branches and trunks. Symptoms and management are described in this factsheet.

Cucumber Mosaic

Cucumber mosaic is a viral disease of worldwide distribution that affects over 1200 plant species. Hosts include a wide range of fruits, vegetables, herbaceous and woody ornamentals, and weeds. This factsheet covers identification and ways to prevent this incurable disease.

Root-Knot Nematode

Root-knot nematodes (Meloidogyne spp.) are small, soilborne, worm-like organisms that infect many agricultural and horticultural plants. This publication describes the symptoms, management and control of root-knot nematodes in Wisconsin.

Foliar Nematodes

Foliar nematodes are microscopic worm-like organisms in the genus Aphelenchoides. They live in and on the leaves (and other above-ground plants parts) of over 450 plant species in more than 75 plant families. They are commonly found on hostas, but can affect other herbaceous ornamentals. Learn what to look for and how to manage foliar nematodes in this factsheet.

Southern Blight

Authors: Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Last Revised: 01/03/2019 X-number: XHT1042   What is Southern blight?  Southern blight is a lethal fungal disease that is most common in the tropics and subtropics.  This disease causes damage in the southern U.S. and can even cause problems in temperate locations like Wisconsin during periods of warm, moist […]

Crown Gall

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  5/5/2005 Item number:  XHT1037 What is a crown gall?  Crown gall is the most widely distributed bacterial disease of plants in the world, affecting over 100 species of fruit crops, and woody and herbaceous ornamentals, including rose, euonymus, lilac, poplar, viburnum, willow, apple, pear, brambles, stone […]

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