University of Illinois Extension

University of Illinois Extension

Hort Answers

Browse Plant Pests and Problems

Fungal Disease
Anthracnose [Annuals and Perennials]
Anthracnose [Annuals and Perennials]
Many genus and species involved
Fungal Disease
Anthracnose [Trees and Shrubs]
Anthracnose [Trees and Shrubs]
Many genus and species involved
Fungal Disease
Anthracnose [Turfgrass]
Anthracnose [Turfgrass]
Colletotrichum graminicola
 
Fungal Disease
Anthracnose [Vegetables]
Anthracnose [Vegetables]
Colletotrichum spp.
Fungal Disease
Apple scab
Apple scab
Venturia inaequalis
Fungal Disease
Black Knot
Black Knot
Apiosporina morbosa [syn. Dibotryon morbosum]
 
Fungal Disease
Black Spot
Black Spot
Diplocarpon rosae
Fungal Disease
Botryosphaeria Dieback/Canker
Botryosphaeria Dieback/Canker
Botryosphaeria dothidea
Fungal Disease
Brown Patch [Turfgrass]
Brown Patch [Turfgrass]
Rhizoctonia solani
 
Fungal Disease
Brown Spot
Brown Spot
Mycosphaerella dearnessii (Scirrhia acicola)
Fungal Disease
Cankers on Pine
Cankers on Pine
Botryosphaeria spp. and other canker fungi
Fungal Disease
Cankers on Rose
Cankers on Rose
Coniothyrium, Phomopsis, Botryosphaeria, Botrytis and others
 
Fungal Disease
Cedar Rust Diseases
Cedar Rust Diseases
several
Fungal Disease
Cedar-Apple Rust
Cedar-Apple Rust
Gymnosporangium juniperi-virginianae
Fungal Disease
Cedar-Hawthorn Rust
Cedar-Hawthorn Rust
Gymnosporangium globosum
 
Fungal Disease
Cedar-Quince Rust
Cedar-Quince Rust
Gymnosporangium clavipes
Fungal Disease
Cercospora Blight
Cercospora Blight
Cercospora sequoiae juniperi
Fungal Disease
Coneflower problems
Coneflower problems
 
Fungal Disease
Coral Bells diseases
Coral Bells diseases
Heuchera sp.
Fungal Disease
Cytospora Canker of Spruce
Cytospora Canker of Spruce
Leucostoma kunzei (Cytospora kunzei)
Fungal Disease
Daylily problems
Daylily problems
 
Fungal Disease
Dieback/Canker
Dieback/Canker
Nectria spp., Phomopsis spp., Botryosphaeria spp., Tubercularia spp., Phytophthora spp.
Fungal Disease
Diplodia Tip Blight & Canker
Diplodia Tip Blight & Canker
Diplodia pinea (Sphaeropsis sapinea)
Fungal Disease
Dogwood Anthracnose
Dogwood Anthracnose
Discula sp.
 
Fungal Disease
Dollar Spot [Turfgrass]
Dollar Spot [Turfgrass]
Rutstroemia floccosum syn. Sclerotinia homoeocarpa
Fungal Disease
Dothistroma Needle Blight
Dothistroma Needle Blight
Dothistroma septospora
Fungal Disease
No Photo
Downy Mildew [Vegetables]
Bremia, Peronospora, and Pseudoperonospora spp.
 
Fungal Disease
Dutch Elm Disease
Dutch Elm Disease
Ophiostoma ulmi [formerly Ceratocystis ulmi] and O. novo-ulmi
Fungal Disease
Early Blight or Alternaria Leaf Spot
Early Blight or Alternaria Leaf Spot
Alternaria spp.
Fungal Disease
Fairy Rings [Turfgrass]
Fairy Rings [Turfgrass]
various Basidiomycete fungi
 
Fungal Disease
Fusarium Wilt [Annuals and Perennials]
Fusarium Wilt [Annuals and Perennials]
Fusarium spp.
Fungal Disease
Gray Leaf Spot [Turfgrass]
Gray Leaf Spot [Turfgrass]
Pyricularia grisea
Fungal Disease
Gray Mold [Annuals and Herbaceous Perennials]
Gray Mold [Annuals and Herbaceous Perennials]
Botrytis cinerea & paeoniae
 
Fungal Disease
Gray Mold [Trees and Shrubs]
Gray Mold [Trees and Shrubs]
Botrytis cinerea and other species
Fungal Disease
Gray Snow Mold [Turfgrass]
Gray Snow Mold [Turfgrass]
Typhula spp.
Fungal Disease
No Photo
Gummy Stem Blight or Black Rot of Cucurbits
Didymella bryonia
 
Fungal Disease
Helminthosporium Leaf Blights of Sweet Corn
Helminthosporium Leaf Blights of Sweet Corn
Several related genera
Fungal Disease
Helminthosporium Leaf, Crown, and Root Diseases [Turfgrass]
Helminthosporium Leaf, Crown, and Root Diseases [Turfgrass]
Several related genera
Fungal Disease
Hollyhock diseases
Hollyhock diseases
Alcea sp.
 
Fungal Disease
Iris problems
Iris problems
Fungal Disease
Kabatina Blight
Kabatina Blight
Kabatina juniperi
Fungal Disease
Leaf Smuts [Turfgrass]
Leaf Smuts [Turfgrass]
Ustilago striiformis and Urocystis agropyri
 
Fungal Disease
Lily-of-the-Valley problems
Lily-of-the-Valley problems
Convallaria sp.
Fungal Disease
Lophodermium Needle Cast
Lophodermium Needle Cast
Lophodermium sp.
Fungal Disease
Marssonia Leaf Spots and Blights
Marssonia Leaf Spots and Blights
Marssonia spp.
 
Fungal Disease
Mushrooms and Puffballs
Mushrooms and Puffballs
various Basidiomycete fungi
Fungal Disease
Oak Leaf Blister
Oak Leaf Blister
Taphrina caerulescens
Fungal Disease
Oak Wilt
Oak Wilt
Ceratocystis fagacearum
 
Fungal Disease
Peach Leaf Curl and Plum Pocket
Peach Leaf Curl and Plum Pocket
Taphrina spp.
Fungal Disease
Peony diseases
Peony diseases
Paeona sp.
Fungal Disease
Pestalotiopsis Blight
Pestalotiopsis Blight
Pestalotiopsis sp.
 
Fungal Disease
Phlox diseases
Phlox diseases
Phlox sp.
Fungal Disease
Phomopsis Gall
Phomopsis Gall
Phomopsis spp.
Fungal Disease
Phomopsis Tip Blight of Juniper
Phomopsis Tip Blight of Juniper
Phomopsis juniperovora
 
Fungal Disease
No Photo
Phytophthora Blight [Vegetables]
Phytophthora spp. [water molds]
Fungal Disease
Phytophthora Canker, Basal Rot, & Root Rot [Shrubs and Trees]
Phytophthora Canker, Basal Rot, & Root Rot [Shrubs and Trees]
Phytophthora spp. [water molds]
Fungal Disease
Pine Cankers and Dieback
Pine Cankers and Dieback
Botryosphaeria dothidea
 
Fungal Disease
Pink Snow Mold [Turfgrass]
Pink Snow Mold [Turfgrass]
Microdochium nivale
Fungal Disease
Powdery Mildew [Annuals and Herbaceous Perennials]
Powdery Mildew [Annuals and Herbaceous Perennials]
Many genus and species involved
Fungal Disease
Powdery Mildew [Shrubs and Trees]
Powdery Mildew [Shrubs and Trees]
Many genus and species involved
 
Fungal Disease
Powdery Mildew [Turfgrass]
Powdery Mildew [Turfgrass]
Blumeria graminis [formerly Erysiphe graminis]
Fungal Disease
Powdery Mildew [Vegetables]
Powdery Mildew [Vegetables]
Erysiphe spp.
Fungal Disease
Pythium Blight [Turfgrass]
Pythium Blight [Turfgrass]
Pythium spp. [water molds]
 
Fungal Disease
Red Thread [Turfgrass]
Red Thread [Turfgrass]
Laetisaria fuciformis
Fungal Disease
Rhizosphaera Needle Cast
Rhizosphaera Needle Cast
Rhizosphaera kalkhoffii
Fungal Disease
Rose Problems
Rose Problems
 
Fungal Disease
Rust [Turfgrass]
Rust [Turfgrass]
Puccinia spp. and Uromyces spp.
Fungal Disease
No Photo
Rusts [Vegetables]
Puccinia and Uromyces spp.
Fungal Disease
No Photo
Scab of Cucurbits
Cladosporium cucumerinum
 
Fungal Disease
Septoria Leaf Spot of Tomato
Septoria Leaf Spot of Tomato
Septoria lycopersici
Fungal Disease
Slime Molds
Slime Molds
Mucilago, Didymium, Physarum, and Fuligo species
Fungal Disease
Smooth Patch
Smooth Patch
Several fungal genera
 
Fungal Disease
SNEED (Sudden Needle Drop or Spruce Needle Drop)
SNEED (Sudden Needle Drop or Spruce Needle Drop)
Fungal Disease
Sooty Mold
Sooty Mold
Numerous genus and species
Fungal Disease
Stigmina needle blight
Stigmina needle blight
Stigmina lautii
 
Fungal Disease
Summer Patch and Necrotic Ring Spot [Turfgrass]
Summer Patch and Necrotic Ring Spot [Turfgrass]
Magnaporthe poae and Leptosphaeria korrae
Fungal Disease
Tulip diseases
Tulip diseases
Tulipa sp.
Fungal Disease
Verticillium Wilt [Annuals and Herbaceous Perennials]
Verticillium Wilt [Annuals and Herbaceous Perennials]
Verticillium albo-atrum and V. dahliae
 
Fungal Disease
Verticillium Wilt [Shrubs and Trees]
Verticillium Wilt [Shrubs and Trees]
Verticillium albo-atrum and V. dahliae
Fungal Disease
No Photo
Verticillium Wilt [Small Fruit Plants]
Verticillium albo-atrum and V. dahliae
Fungal Disease
Verticillium Wilt [Vegetables]
Verticillium Wilt [Vegetables]
Verticillium albo-atrum and V. dahliae
 
Fungal Disease
White Pine Blister Rust
White Pine Blister Rust
Cronartium ribicola
Fungal Disease
No Photo
White Rust [Vegetables]
Albugo spp.
Fungal Disease
No Photo
Witchhazel Leaf Spot
Phyllosticta hamamelidis
 
Fungal Disease
Wood Rots and Decays
Wood Rots and Decays
Many genus and species involved
Fungal Disease
Yarrow problems
Yarrow problems
Achillea sp.