All posts by hudelson

Wisconsin Disease Almanac – June 20, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from June 14, 2025 through June 20, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Boxwood
Disease/Disorder:  Volutella Canker
Pathogen:  Volutella sp.
County:  Dane

Plant:  Buckthorn (Fern Leaf)
Disease/Disorder:  Crown Rust
Pathogen:  Puccinia coronata
County:  Dane

Plant:  Burning Bush
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

Plant:  Cherry (Sand)
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Dane

Plant:  Crabapple
Disease/Disorder:  Apple Scab
Pathogen:  Venturia inaequalis
Counties:  Dane, Racine

Plant:  Crabapple
Disease/Disorder:  Chlorosis
Pathogen:  None
County:  Dane

Plant:  Crabapple
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Dane

Plant:  Elm (Unspecified)
Disease/Disorder:  Dutch Elm Disease
Pathogen:  Ophiostoma sp. 
County:  La Crosse

Plant:  Magnolia
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Dane

Plant:  Maple (Sugar)
Disease/Disorder:  Squirrel Damage
Pathogen:  None
County:  Washington

Plant:  Maple (Unspecified)
Disease/Disorder:  Root/Crown Rot
Pathogens:  Pythium sp., Fusarium sp.
County:  Waukesha

Plant:  Oak (Red)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Waukesha

Plant:  Oak (Red)
Disease/Disorder:  Oak Wilt
Pathogen:  Bretziella fagacearum
County:  Columbia

Plant:  Oak (White)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Lake (IL)

Plant:  Oak (White)
Disease/Disorder:  Chlorosis
Pathogen:  None
County:  Lake (IL)

Plant:  Oak (White)
Disease/Disorder:  Tubakia Leaf Spot
Pathogen:  Tubakia dryina
County:  Lake (IL)

Plant:  Redbud
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Dane

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Field Crops Icon

Field Crops

No New Diseases

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Forage Crops Icon

Forage Crops

No New Diseases

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Fruit Crops Icon

Fruit Crops

Plant:  Plum
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Portage

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Hosta
Disease/Disorder:  Host Virus X (Suspected)
Pathogen:  Hosta virus X
County:  Milwaukee

Plant:  Monarda
Disease/Disorder:  Chemical Burn (Suspected)
Pathogen:  None
County:  Sawyer

Plant:  Pachysandra
Disease/Disorder:  Volutella Blight
Pathogen:  Volutella pachysandricola
County:  Milwaukee

Plant:  Peony
Disease/Disorder:  Root/Crown Rot
Pathogens:  Phytophthora sp., Rhizoctonia sp.
County:  Iowa

Plant:  Phlox
Disease/Disorder:  Chemical Burn (Suspected)
Pathogen:  None
County:  Sawyer

Plant:  St. John’s-Wort
Disease/Disorder:  Rust
Pathogen:  Melampsora hypericorum (Suspected)
County:  La Crosse

Plant:  Veronica
Disease/Disorder:  Chemical Burn (Suspected)
Pathogen:  None
County:  Sawyer

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Houseplants Icon

Houseplants

No New Diseases

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Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Winter Burn (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Fir (White)
Disease/Disorder:  Phyllosticta Needle Blight
Pathogen:  Phyllosticta sp.
County:  Dane

Plant:  Juniper
Disease/Disorder:  Cedar-Quince Rust
Pathogen:  Gymnosporangium clavipes
County:  Dane

Plant:  Juniper
Disease/Disorder:  Cytospora Canker
Pathogen:  Cytospora sp.
County:  Waukesha

Plant:  Juniper
Disease/Disorder:  Phomopsis Tip Blight
Pathogen:  Phomopsis juniperovora
County:  Dane

Plant:  Juniper
Disease/Disorder:  Stigmina Needle Blight
Pathogen:  Stigmina juniperina
County:  Waukesha

Plant:  Juniper
Disease/Disorder:  Winter Burn 
Pathogen:  None
County:  Waukesha

Plant:  Yew
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Waukesha

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Vegetable Crops Icon

Vegetable Crops

Plant:  Onion
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Dodge

Plant:  Pea
Disease/Disorder:  Root Rot
Pathogens:  Aphanomyces euteiches, Fusarium sp., Pythium sp., Rhizoctonia sp. 
County:  Waushara

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Specialty Crops Icon

Specialty Crops

No New Diseases

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Miscellaneous Icon

Miscellaneous

Mushroom ID:  Dead Man’s Fingers (Xylaria polymorpha) 
County: Winnebago

Mushroom ID:  Varnish Shelf (Ganoderma sp.) 
County:  Winnebago

Mushroom ID:  Glistening Inky Cap (Coprinellus micaceus) 
County: Waukesha

Mushroom ID:  Woodland Inkcap (Coprinellus deliquescens) 
County:  Waukesha

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Wisconsin Disease Almanac – June 13, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from June 7, 2025 through June 13, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Boxwood
Disease/Disorder:  Volutella Canker
Pathogen:  Volutella sp.
County:  Brown

Plant:  Buckthorn (Unspecified)
Disease/Disorder:  Crown Rust
Pathogen:  Puccinia coronata
County:  Washington

Plant:  Dogwood (Unspecified)
Disease/Disorder:  Botryosphaeria Canker
Pathogen:  Botryosphaeria sp.
County:  Ozaukee

Plant:  Oak (Red)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Waukesha

Plant:  Oak (Unspecified)
Disease/Disorder:  Anthracnose (Suspected)
Pathogen:  Discula sp.
County:  Waukesha

Plant:  Redbud
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Dane

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Field Crops Icon

Field Crops

No New Diseases

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Forage Crops Icon

Forage Crops

No New Diseases

(Back To Menu)


Fruit Crops Icon

Fruit Crops

No New Diseases

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Peony
Disease/Disorder:  Root/Crown Rot
Pathogen:  Phytophthora sp.
County:  Dane

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Houseplants Icon

Houseplants

No New Diseases

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Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Root/Crown Rot
Pathogen:  Pythium sp.
County:  Milwaukee

Plant:  Juniper
Disease/Disorder:  Winter Burn (Suspected)
Pathogen:  None
County:  Washington

Plant:  Juniper
Disease/Disorder:  Winter Burn 
Pathogen:  None
County:  Waukesha

Plant:  Pine (Scots)
Disease/Disorder:  Diplodia Shoot Blight and Canker
Pathogen:  Diplodia sp.
County:  Dane

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Vegetable Crops Icon

Vegetable Crops

No New Diseases

(Back To Menu)


Specialty Crops Icon

Specialty Crops

No New Diseases

(Back To Menu)


Miscellaneous Icon

Miscellaneous

No New Reports

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Wisconsin Disease Almanac – June 6, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 31, 2025 through June 6, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Aspen
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

Plant:  Buckthorn (Fern Leaf)
Disease/Disorder:  Crown Rust
Pathogen:  Puccinia coronata
County:  Dane

Plant:  Hawthorn
Disease/Disorder:  Cedar-Quince Rust
Pathogen:  Gymnosporangium clavipes
County:  Dane

Plant:  Hawthorn
Disease/Disorder:  Improper Planting
Pathogen:  None
County:  Dane

Plant:  Lilac (Japanese Tree)
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Dane

Plant:  Maple (Unspecified)
Disease/Disorder:  Anthracnose
Pathogen:  Discula sp.
County:  Lafayette

Plant:  Oak (Bur)
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

Plant:  Rose
Disease/Disorder:  Phomopsis/Diaporthe Canker
Pathogen:  Phomopsis sp./Diaporthe sp.
County:  Milwaukee

Plant:  Rose
Disease/Disorder:  Virus Disease
Pathogen:  Unspecified virus
County:  Milwaukee

Plant:  Witch-Hazel
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dodge

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Field Crops Icon

Field Crops

No New Diseases

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Forage Crops Icon

Forage Crops

No New Diseases

(Back To Menu)


Fruit Crops Icon

Fruit Crops

Plant:  Peach
Disease/Disorder: Peach Leaf Curl
Pathogen:  Taphrina deformans
Counties:  Washington, Waukesha

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Geranium (Perennial)
Disease/Disorder:  Polygonum-Geranium Rust
Pathogen:  Puccinia polygoni-amphibii
County:  Rock

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Houseplants Icon

Houseplants

No New Diseases

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Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Urine Damage (Suspected)
Pathogen:  None
County:  Milwaukee

Plant:  Pine (Red)
Disease/Disorder:  Diplodia Shoot Blight and Canker
Pathogen:  Diplodia sp.
County:  Dane

Plant:  Pine (White)
Disease/Disorder:  White Pine Blister Rust
Pathogen:  Cronartium ribicola
County:  Dane

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Vegetable Crops Icon

Vegetable Crops

No New Diseases

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Specialty Crops Icon

Specialty Crops

No New Diseases

(Back To Menu)


Miscellaneous Icon

Miscellaneous

No New Reports

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Wisconsin Disease Almanac – May 30, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 24, 2025 through May 30, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Aspen
Disease/Disorder:  Venturia Leaf and Shoot Blight
Pathogen:  Venturia moreletii
County:  La Crosse

Plant:  Boxwood
Disease/Disorder:  Fusarium Canker
Pathogen:  Fusarium sp.
County:  Waukesha

Plant:  Boxwood
Disease/Disorder:  Volutella Canker
Pathogen:  Volutella sp.
County:  Waukesha

Plant:  Oak (Unspecified)
Disease/Disorder:  Armillaria Root Disease (Suspected)
Pathogen:  Armillaria sp.
County:  Dane

Plant:  Pear (Callery)
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Rhododendron
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Washington

Plant:  Rhododendron
Disease/Disorder:  Seimatosporium Leaf Spot
Pathogen:  Seimatosporium sp.
County:  Washington

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Field Crops Icon

Field Crops

No New Diseases

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Forage Crops Icon

Forage Crops

No New Diseases

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Fruit Crops Icon

Fruit Crops

Plant:  Gooseberry
Disease/Disorder:  Gooseberry Rust
Pathogen:  Puccinia caracina var. pringsheimiana
County:  Dane

Plant:  Peach
Disease/Disorder: Peach Leaf Curl
Pathogen:  Taphrina deformans
County:  Dane

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Pachysandra
Disease/Disorder:  Volutella Blight
Pathogen:  Volutella pachysandricola
Counties:  Milwaukee, Waukesha

Plant:  Pansy
Disease/Disorder:  Root Rot
Pathogens:  Phytophthora sp., Rhizoctonia sp.
County:  Kenosha

Plant:  Peony
Disease/Disorder:  Cold Injury
Pathogen:  None
County:  Vernon

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Houseplants Icon

Houseplants

No New Diseases

(Back To Menu)


Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Transplant Shock (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Arborvitae
Disease/Disorder:  Urine Damage (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Fir (Unspecified)
Disease/Disorder:  Phyllosticta Needle Blight
Pathogen:  Phyllosticta sp.
County:  Waukesha

Plant:  Spruce (Unspecified)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Clark

Plant:  Spruce (Unspecified)
Disease/Disorder:  Rhizosphaera Needle Cast (Suspected)
Pathogen:  Rhizosphaera kalkhoffii
County:  Saratoga (NY)

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Vegetable Crops Icon

Vegetable Crops

No New Diseases

(Back To Menu)


Specialty Crops Icon

Specialty Crops

No New Diseases

(Back To Menu)


Miscellaneous Icon

Miscellaneous

Mushroom ID:  Glistening Inky Cap (Coprinellus micaceus) 
County:  Dane

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Wisconsin Disease Almanac – May 23, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 17, 2025 through May 23, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Boxwood
Disease/Disorder:  Volutella Canker
Pathogen:  Volutella sp.
County:  Waukesha

Plant:  Crabapple
Disease/Disorder:  Lichens
Pathogen:  None
County:  Florence

Plant:  Crabapple
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Dane

Plant:  Crabapple
Disease/Disorder:  Sapsucker Damage
Pathogen:  None
County:  Florence

Plant:  Crabapple
Disease/Disorder:  Sphaeropsis Canker
Pathogen:  Sphaeropsis sp.
County:  Dane

Plant:  Lilac
Disease/Disorder:  Ascochyta Leaf Blight
Pathogen:  Ascochyta sp.
County:  Walworth

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Field Crops Icon

Field Crops

No New Diseases

(Back To Menu)


Forage Crops Icon

Forage Crops

No New Diseases

(Back To Menu)


Fruit Crops Icon

Fruit Crops

Plant:  Apple
Disease/Disorder:  Sooty Mold
Pathogen:  Miscellaneous sooty mold fungi
County:  Iowa

Plant:  Plum
Disease/Disorder: Black Knot
Pathogen:  Apiosporina morbosa
County:  Jefferson

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Pachysandra
Disease/Disorder:  Volutella Blight
Pathogen:  Volutella pachysandricola
Counties:  Columbia, Waukesha

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Houseplants Icon

Houseplants

No New Diseases

(Back To Menu)


Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Phyllosticta Needle Blight
Pathogen:  Phyllosticta sp.
County:  Waukesha

Plant:  Fir (White)
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  Dane

Plant:  Juniper
Disease/Disorder: Phomopsis Tip Blight
Pathogen:  Phomopsis juniperovora
County:  Milwaukee

Plant:  Juniper
Disease/Disorder: Winter Burn (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Spruce (Norway)
Disease/Disorder: Winter Burn (Suspected)
Pathogen:  None
Counties:  Milwaukee, Washington

Plant:  Spruce (Unspecified)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Dane

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Vegetable Crops Icon

Vegetable Crops

Plant:  Cabbage
Disease/Disorder:  Damping-Off
Pathogen:  Pythium sp.
County:  Waushara

Plant:  Cantaloupe
Disease/Disorder:  Damping-Off
Pathogen:  Pythium sp.
County:  Monroe

Plant:  Pea
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Waushara

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Specialty Crops Icon

Specialty Crops

No New Diseases

(Back To Menu)


Miscellaneous Icon

Miscellaneous

No New Reports

(Back To Menu)


 

Wisconsin Disease Almanac – May 16, 2025

No Date Icon

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 10, 2025 through May 16, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Hickory
Disease/Disorder:  Phomopsis Gall
Pathogen:  Phomopsis sp.
County:  Door

Plant:  Oak (Unspecified)
Disease/Disorder:  Armillaria Root Disease
Pathogen:  Armillaria sp.
County:  Walworth

Plant:  Trees and shrubs (Miscellaneous)
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

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Field Crops Icon

Field Crops

No New Diseases

(Back To Menu)


Forage Crops Icon

Forage Crops

No New Diseases

(Back To Menu)


Fruit Crops Icon

Fruit Crops

Plant:  Apple
Disease/Disorder:  Phomopsis Canker
Pathogen:  Phomopsis sp.
County:  St. Croix

Plant:  Apple
Disease/Disorder: Transplant Shock (Suspected)
Pathogen:  None
County:  St. Croix

Plant:  Apple
Disease/Disorder:  Winter Injury (Suspected)
Pathogen:  None
County:  St. Croix

Plant:  Raspberry
Disease/Disorder:  Root Rot
Pathogen:  Phytophthora sp.
County:  Milwaukee

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Bergenia
Disease/Disorder:  Transplant Shock (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Bergenia
Disease/Disorder:  Winter Injury (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Herbaceous Ornamentals (Miscellaneous)
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

Plant:  Monarda
Disease/Disorder:  Gray Mold (Botrytis Blight)
Pathogen:  Botrytis sp.
County:  Green

Plant:  Monarda
Disease/Disorder:  Winter Injury (Suspected)
Pathogen:  None
County:  Green

Plant:  Pachysandra
Disease/Disorder:  Volutella Blight
Pathogen:  Volutella pachysandricola
Counties:  Milwaukee, Waukesha

Plant:  Pachysandra
Disease/Disorder:  Winter Injury (Suspected)
Pathogen:  None
County:  Milwaukee

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Houseplants Icon

Houseplants

No New Diseases

(Back To Menu)


Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Phyllosticta Needle Blight
Pathogen:  Phyllosticta sp.
County:  Dane

Plant:  Arborvitae
Disease/Disorder:  Root Rot
Pathogen:  Phytophthora sp.
County:  Dane

Plant:  Arborvitae
Disease/Disorder:  Transplant Shock (Suspected)
Pathogen:  None
County:  Grant

Plant:  Arborvitae
Disease/Disorder:  Water Stress (Suspected)
Pathogen:  None
County:  Dane

Plant:  Arborvitae
Disease/Disorder: Winter Burn (Suspected)
Pathogen:  None
County:  Grant

Plant:  Juniper
Disease/Disorder:  Winter Burn (Suspected)
Pathogen:  None
Counties:  Milwaukee, Sheboygan

Plant:  Pine (Japanese White)
Disease/Disorder:  Cyclaneusma Needle Blight
Pathogen:  Cyclaneusma minus
County:  Dane

Plant:  Pine (White)
Disease/Disorder:  White Pine Blister Rust
Pathogen:  Cronartium ribicola
County:  Dane

Plant:  Spruce (Black Hills)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Dodge

Plant:  Spruce (Blue)
Disease/Disorder:  Rhizosphaera Needle Cast (Suspected)
Pathogen:  Rhizosphaera kalkhoffii
County:  Dunn

Plant:  Spruce (White)
Disease/Disorder:  Fertility Issues (Suspected)
Pathogen:  None
County:  Dane

Plant:  Spruce (White)
Disease/Disorder: Winter Burn (Suspected)
Pathogen:  None
County:  Dane

Plant:  Trees and shrubs (Miscellaneous)
Disease/Disorder:  Herbicide Damage
Pathogen:  None
County:  Dane

Plant:  Yew
Disease/Disorder:  Twig Blight
Pathogen:  Sphaeropsis sp.
County:  Dane

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Vegetable Crops Icon

Vegetable Crops

No New Diseases

(Back To Menu)


Specialty Crops Icon

Specialty Crops

No New Diseases

(Back To Menu)


Miscellaneous Icon

Miscellaneous

No New Reports

(Back To Menu)


 

Wisconsin Disease Almanac – May 9, 2025

No Date Icon

Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from May 3, 2025 through May 9, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

Plant:  Crabapple
Disease/Disorder:  Lichens
Pathogen:  None
County:  Dane

Plant:  Oak (Unspecified)
Disease/Disorder:  Armillaria Root Disease
Pathogen:  Armillaria sp.
County:  Waukesha

Plant:  Oak (Unspecified)
Disease/Disorder:  White Rot
Pathogen:  Trichaptum biforme
County:  Waukesha

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Field Crops Icon

Field Crops

No New Diseases

(Back To Menu)


Forage Crops Icon

Forage Crops

No New Diseases

(Back To Menu)


Fruit Crops Icon

Fruit Crops

Plant:  Apple
Disease/Disorder:  Frost Crack
Pathogen:  None
County:  Sauk

Plant:  Apple
Disease/Disorder:  Sap Rot
Pathogen:  Schizophyllum commune
County:  Sauk

Plant:  Nectarine
Disease/Disorder:  Peach Leaf Curl
Pathogen:  Taphrina deformans
County:  Nassau (NY)

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Geranium
Disease/Disorder:  Iron/Manganese Toxicity (Suspected)
Pathogen:  None
County:  Dane

Plant:  Lobelia
Disease/Disorder:  Heat Stress (Suspected)
Pathogen:  None
County:  Jefferson

Plant:  Pachysandra
Disease/Disorder:  Volutella Blight
Pathogen:  Volutella pachysandricola
Counties:  Milwaukee, Waukesha

Plant:  Pachysandra
Disease/Disorder:  Winter Injury (Suspected)
Pathogen:  None
Counties:  Milwaukee, Waukesha

Plant:  Phlox (Garden)
Disease/Disorder:  Phytoplasma Disease
Pathogen:  Unspecified Phytoplasma
County:  Green

Plant:  Phlox (Garden)
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Green

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Houseplants Icon

Houseplants

No New Diseases

(Back To Menu)


Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Cytospora Canker
Pathogen:  Cytospora sp.
County:  Milwaukee

Plant:  Arborvitae
Disease/Disorder:  Root Rot
Pathogen:  Phytophthora sp.
County:  Waukesha

Plant:  Hemlock (Eastern)
Disease/Disorder:  Root Rot
Pathogen:  Phytophthora sp.
County:  Dane

Plant:  Juniper
Disease/Disorder:  Winter Burn (Suspected)
Pathogen:  None
County:  Milwaukee

Plant:  Pine (Scots)
Disease/Disorder:  Diplodia Shoot Blight and Canker
Pathogen:  Diplodia sp.
County:  Waukesha

Plant:  Spruce (Norway)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Waukesha

Plant:  Spruce (Unspecified)
Disease/Disorder:  Spruce Needle Drop
Pathogen:  Setomelanomma holmii
County:  Waukesha

Plant:  Spruce (Unspecified)
Disease/Disorder:  Transplant Shock
Pathogen:  None
County:  Dane

Plant:  Spruce (Unspecified)
Disease/Disorder:  Water Stress
Pathogen:  None
County:  Waukesha

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Vegetable Crops Icon

Vegetable Crops

No New Diseases

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Specialty Crops Icon

Specialty Crops

No New Diseases

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Miscellaneous Icon

Miscellaneous

No New Reports

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Wisconsin Disease Almanac – May 2, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from April 26, 2025 through May 2, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

No New Diseases

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Field Crops Icon

Field Crops

No New Diseases

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Forage Crops Icon

Forage Crops

No New Diseases

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Fruit Crops Icon

Fruit Crops

No New Diseases

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Vinca
Disease/Disorder:  Winter Burn (Suspected)
Pathogen:  None
County:  Dane

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Houseplants Icon

Houseplants

No New Diseases

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Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Juniper
Disease/Disorder:  Cedar-Quince Rust (Suspected)
Pathogen:  Gymnosporangium clavipes
County:  Ozaukee

Plant:  Pine (Red)
Disease/Disorder:  Brown Spot (Suspected)
Pathogen:  Lecanosticta acicola
County:  Waukesha

Plant:  Pine (Red)
Disease/Disorder:  Ozone Damage (Suspected)
Pathogen:  None
County:  Waukesha

Plant:  Spruce (Norway)
Disease/Disorder:  Spruce Needle Drop
Pathogen:  Setomelanomma holmii
County:  Jefferson

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Vegetable Crops Icon

Vegetable Crops

Plant:  Garlic
Disease/Disorder:  Aerial Blight
Pathogen:  Rhizoctonia sp.
County:  Richland

Plant:  Garlic
Disease/Disorder:  Root Rot
Pathogen:  Pythium sp.
County:  Richland

Plant:  Tomato
Disease/Disorder:  Edema
Pathogen:  None
County:  Taylor

Plant:  Tomato
Disease/Disorder:  Ethylene Damage (Suspected)
Pathogen:  None
County:  Taylor

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Specialty Crops

No New Diseases

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Miscellaneous Icon

Miscellaneous

No New Reports

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April 2025: The Root of the Problem

Roots IconAs I commented in my March 2025 web article, the 2024 growing season was incredibly wet, and as a consequence, I observed an uptick in foliar diseases such as apple scab and Septoria leaf spot of lilac.  But, it wasn’t only leaves that had problems due to the wet weather.  A lot of last year’s rain ended up in the soil, and the resulting wet soil conditions contributed to an increase in root rots and related diseases. 

Rot roots

Root rots are caused by a wide variety of organisms including (but not limited to) Rhizoctonia, Pythium, and Phytophthora,Rhizoctonia is a true fungus, while Pythium and Phytophthora fall into a group of fungi-like organisms called the water molds.   Water  mold root rot pathogens tend to be particularly aggressive and also tend to be long-lived.  They produce thick-walled resting spores (called oospores) that can survive for years, if not decades, in the soil.  Under hotter, drier conditions, these spores germinate to form hyphae (i.e., fungal threads) that can directly infect plant roots.  Under cooler, wetter conditions, oospores germinate in a different manner, eventually producing numerous smaller, swimming spores called zoospores.  These spores swim to plant roots where they infect.  Production of zoospores significantly increases a water mold’s ability to infect, leading to an increase in the number of infections and subsequent disease severity. 

Browning of the lower trunk and roots of a tree typical of root and crown rot
Browning of the lower trunk and roots of a tree typical of root and crown rot.

Root rot pathogen infections directly lead to root decay and deterioration.  Roots are typically discolored (e.g., brown, black), as well as soft and mushy.  This decay interferes with a plant’s ability to take up water and nutrients.  Indirect effects due to root rots include leaf symptoms that might be misidentified as being due to poor fertility (e.g., yellowing or reddening), symptoms that might be mistaken for drought stress symptoms (e.g., marginal leaf browning), wilting and branch dieback, and, ultimately, plant death. 

Once symptoms of root rots are observed, often there is little one can do to correct the problem.  Root rots are best managed preemptively at the time that gardens and landscapes are established.  Modifying soils to improve drainage (e.g., by adding organic matter), and choosing plants that are adapted to the soil moisture conditions at a particular site are two ways to prevent root rot issues.  There are potentially fungicides that can be used for management of root rots.  However, for these treatments to be effective, early diagnosis of the problem (i.e., before there is extensive root damage) is critical.  Fungicides, for the most part, do not cure existing infections, but help protect new roots from being infected.  Before applying fungicides, proper identification of the organism(s) involved in a root rot problem is extremely important; the fungicides needed to manage fungal vs. water mold root rot pathogens are quite different.  Often, plants have problems with both fungal and water mold root rotters simultaneously, so use of multiple active ingredients is needed for control.  Note that root rot fungicides typically are not readily available to homeowners, so contracting with a professional pesticide applicator to make treatments  will likely be necessary.  As you can imagine, using fungicides for root rot control can get very expensive, very quickly. 

Related diseases

A variant of root rots that I encountered several times last summer and have already encountered in 2025, is bleeding cankers on trees (e.g., maple, beech, birch).  Typical symptoms of bleeding cankers are a series of wet, oozy spots on tree trunks.  Sometimes these areas are near the soil surface; other times, the oozing occurs farther up on the trunks.  The most typical cause of bleeding cankers on common landscape shade trees is Phytophthora (which I mentioned above in the context of root rots).  When people contact me about bleeding cankers, I request that they send me blobs of the ooze and/or small bits of the ooze-soaked bark (about the equivalent of a 2 inch by 2 inch bark piece).  I test this material with a dipstick serological test for Phytophthora.  This test uses similar technology to that used in home pregnancy tests and home COVID-19 tests. 

Bleeding cankers caused by Phytophthora cactorum on a beech tree trunk.
Bleeding cankers caused by Phytophthora cactorum on a beech tree trunk. Photo courtesy of John Hartman, University of Kentucky, Bugwood.org.

The real fun begins if I get a positive reaction from my initial testing (and many of the samples I have received have tested positive).  At that point, I have to forward the sample to the WI DATCP Plant Industry Lab for further testing.  One of the species of Phytophthora that can cause bleeding cankers is Phytophthora ramorum.  This organism causes sudden oak death/Ramorum blight and is highly regulated at both the state and federal level, because of how destructive it can be.  I need to make sure that samples that test positive for Phytophthora are not infected with Phytophthora ramorumPhytophthora ramorum has occasionally be detected by WI DATCP in nursery stock brought into Wisconsin from other states.  However, Phytophthora ramorum has never been detected in Wisconsin in established landscapes plants.  Luckily, none of the samples that I have submitted to WI DATCP has tested positive for Phytophthora ramorum.  Typically, the Phytophthora species present in my samples has been Phytophthora cactorum, a common Phytophthora species that can cause root rots on a wide range of plant species.

Need help?

Hopefully, you will never have problems with root rots or bleeding cankers in your gardens and landscapes.  If you do however, I encourage you to submit samples for a proper diagnosis.  If you have questions about any plant disease that you are seeing or questions about sample submission, please feel free to contact me at (608) 262-2863 or pddc@wisc.edu.  For additional information on plant diseases and their management, be sure to check out the UW-Madison PDDC website (https://pddc.wisc.edu/).  To keep up to date on clinic activities and resources, follow the PDDC on Facebook, Twitter (X), or Bluesky (@UWPDDC), or subscribe to the clinic’s listserv, UWPDDCLearn (by emailing or phoning the clinic to subscribe). 

Keep on gardening, and have a great spring and summer!

Wisconsin Disease Almanac – April 25, 2025

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Compiled by Brian Hudelson and Dante Tauscheck

The following diseases/disorders were identified at the Plant Disease Diagnostics Clinic from April 19, 2025 through April 25, 2025.

 

 


Broad-Leafed Woody Ornamentals Icon

Broad-Leafed Woody Ornamentals

No New Diseases

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Field Crops Icon

Field Crops

No New Diseases

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Forage Crops Icon

Forage Crops

No New Diseases

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Fruit Crops Icon

Fruit Crops

Plant:  Blueberry
Disease/Disorder:  Cold Injury (Suspected)
Pathogen:  None
County:  Vernon

Plant:  Blueberry
Disease/Disorder:  Lichens
Pathogen:  None
County:  Vernon

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Herbaceous Ornamentals Icon

Herbaceous Ornamentals

Plant:  Astilbe
Disease/Disorder:  Tobacco Rattle
Pathogen:  Tobacco rattle virus
County:  Jefferson

Plant:  Pachysandra
Disease/Disorder:  Volutella Blight
Pathogen:  Volutella pachysandricola
County:  Waukesha

Plant:  Pachysandra
Disease/Disorder:  Winter Burn
Pathogen:  None
County:  Waukesha

Plant:  Tradescantia
Disease/Disorder:  Tobacco Rattle
Pathogen:  Tobacco rattle virus
County:  Jefferson

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Houseplants Icon

Houseplants

Plant:  Hibiscus
Disease/Disorder:  Fertility Issues (Suspected)
Pathogen:  None
County:  Waukesha

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Needled Woody Ornamentals Icon

Needled Woody Ornamentals

Plant:  Arborvitae
Disease/Disorder:  Root Rot
Pathogen:  Phytophthora sp.
County:  Waukesha

Plant:  Pine (Japanese White)
Disease/Disorder:  Artillery fungus 
Pathogen:  None
County:  Dane

Plant:  Spruce (Norway)
Disease/Disorder:  Hail Damage
Pathogen:  None
County:  Dane

Plant:  Spruce (Norway)
Disease/Disorder:  Spruce Needle Drop
Pathogen:  Setomelanomma holmii
County:  Racine

Plant:  Spruce (Unspecified)
Disease/Disorder:  Rhizosphaera Needle Cast
Pathogen:  Rhizosphaera kalkhoffii
County:  Waukesha

Plant:  Spruce (Unspecified)
Disease/Disorder:  Water Stress (Suspected)
Pathogen:  None
County:  Waukesha

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Vegetable Crops Icon

Vegetable Crops

No New Diseases

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Specialty Crops Icon

Specialty Crops

No New Diseases

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Miscellaneous Icon

Miscellaneous

No New Reports

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