Daylily Leaf Streak

Leaf streak is a common disease of daylilies, affecting daylilies wherever they are grown. Daylily varieties can vary widely in terms of their susceptibility to the disease. Oftentimes leaf streak is a cosmetic problem, causing little damage, but sometimes can cause substantial leaf loss or complete defoliation of daylily plants. Learn how to manage this disease in this factsheet.

Hollyhock Rust

Nicole Uelmen*, UW-Madison Plant Pathology Revised:  3/6/2014 Item number:  XHT1231 What is hollyhock rust?  Hollyhock rust is the most common fungal leaf disease of hollyhocks (Alcea rosea).  Many other ornamentals (e.g., flowering maple, rose mallow) and weeds (e.g., common mallow) in the mallow family are also susceptible.  Hollyhock rust can quickly spread, causing stunting of […]

Impatiens Downy Mildew

Jenna Lind, UW-Madison Plant Pathology Revised:  6/24/2013 Item number:  XHT1223 What is impatiens downy mildew?  Impatiens downy mildew is a disease that has become a serious threat wherever impatiens are grown.  The disease has recently become a serious issue in the United States, including Wisconsin.  Impatiens downy mildew has been so destructive in many areas […]

Ralstonia Wilt

Pest Alert Authors: Brian Hudelson, UW-Madison Plant Pathology Last Revised: 05/01/2020 X-number: XHT1011 What is Ralstonia wilt?  Ralstonia wilt (also sometimes known as Southern wilt) is a usually lethal disease that affects over 250 plants in over 40 plant families.  Susceptible greenhouse-grown ornamentals include, but are not limited to, plants in the genera Capsicum, Cosmos, Cyclamen, Dahlia, Fuschsia, Gerbera, Hydrangea, Impatiens, Lantana, Nasturtium and Pelargonium.  Vegetables such as eggplant, pepper, potato […]

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 […]

Root Rots on Houseplants

Brian Hudelson, UW-Madison Plant Pathology and Laura Jull, UW-Horticulture Revised:  4/25/2004 Item number:  XHT1071 What is root rot?  Root rot is a general term that describes any disease where the pathogen (causal organism) causes the deterioration of a plant’s root system.  Most plants are susceptible to root rots, including both woody and herbaceous ornamentals.  Root […]

Volutella Blight

Gina Muscato and Brian Hudelson, UW-Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1191 What is Volutella blight?  Volutella blight is a common and potentially lethal disease of Japanese pachysandra (Pachysandra terminalis), an evergreen, semi-woody groundcover that is grown in shade gardens throughout hardiness zones 4 and 5 in Wisconsin.  Volutella blight can severely limit the […]

White Mold

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  4/25/2004 Item number:  XHT1115 What is white mold?  White mold is a serious, and often lethal, fungal disease that affects over 374 types of plants in many plant families.  It causes severe damage in commercial snap, kidney and lima bean production, as well as commercial sunflower […]

Edema

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  2/17/2012 Item number:  XHT1116 What is edema?  Edema (or oedema) is a physiological disorder that frequently occurs in houseplants, greenhouse plants, and other plants sheltered under plastic.  This disorder also affects field-grown vegetable crops under certain environmental conditions.  Edema is often a cosmetic problem, but in […]

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 […]

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 […]

Winter Salt Injury and Salt-tolerant Landscape Plants

Laura Jull, UW-Extension Revised:  8/13/2012 Item number:  A3877 This publication focuses on recognizing and preventing plant damage caused by deicing salts, evaluates the pros and cons of alternatives to rock salt, and provides an extensive list of salt-tolerant plants.   Download Article

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