Powdery Mildew – Herbaceous Ornamentals
Powdery Mildew is a disease of many plants. It causes a white, powdery appearance on leaves and flowers. Learn how to manage this common disease in this factsheet.
Diseases & Disorders
Hot-Water Seed Treatment for Disease Management
Growing vegetables from seed is common for many home gardeners, but seed can sometimes be contaminated with disease-causing organisms. Learn about hot water seed treatment to reduce pathogens in this guide.
Cucumber Mosaic
Cucumber mosaic is a viral disease that affects a wide range of fruits, vegetables, herbaceous and woody ornamentals, and weeds. This factsheet covers identification and ways to prevent this incurable disease.
Gladiolus Disorder: Virus Complex and Aster Yellows
Viruses can destroy the value of a gladiolus crop. Serious infections have been observed throughout Wisconsin in some years. While Aster Yellows is common, it usually infects just a few gladioli scattered in plantings. This fact sheet covers the symptoms, causes, and means of control of viral and Aster Yellows infection.
Hosta Virus X
Hosta virus X (HVX) is a viral disease that causes serious problems on many hosta cultivars, causing nursery owners and gardeners in the United States to voluntarily destroy large numbers of hosta to help prevent the spread. This fact sheet describes the symptoms and management of this virus.
Root-Knot Nematode
Root-knot nematodes are small, soilborne, worm-like organisms that infect many agricultural and horticultural plants. This publication describes the symptoms, and management of root-knot nematodes in Wisconsin.
Foliar Nematodes
Foliar nematodes are microscopic worm-like organisms that live in and on leaves (and other above-ground plants parts). Learn what to look for and how to manage foliar nematodes in this factsheet.
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
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 plants and premature leaf drop. In rare instances, hollyhock rust […]
Impatiens Downy Mildew
What is impatiens downy mildew? Impatiens downy mildew is a serious threat wherever impatiens are grown, including Wisconsin. Impatiens downy mildew has been so destructive in the past that it has made impatiens unusable as a garden ornamental. The disease affects garden impatiens (Impatiens walleriana and I. balsamina), as well as native jewelweeds (I. pallida and I. capensis). New […]
Ralstonia Wilt
Ralstonia wilt is a usually lethal disease that affects a wide variety of vegetable and ornamental plants. Learn about symptoms and how to avoid problems with Ralstonia in this factsheet.
Southern Blight
Southern blight is a lethal fungal disease that is most common in the tropics and subtropics, but can cause problems in temperate locations like Wisconsin during periods of warm, moist weather. Learn more here.
