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Lipstick Rust Host: Chinese juniper, apple, crabapple Pathogen: Gymnosporangium yamadae Signs/Symptoms: Brown blobs with orange gelatinous masses (juniper), red leaf spots (apple, crabapple) |
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Boxwood Blight Host: Boxwood Pathogens: Calonectria pseudonaviculata Signs/Symptoms: Circular, brown leaf spots followed by leaf drop and shrub death For more information see: UW Plant Disease Facts D0023 |
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Late Blight Host: Tomato, potato Pathogen: Phytophthora infestans Signs/Symptoms: Water-soaked spots on leaves, leathery areas on tomato fruits, rapid plant death For more information see: UW Plant Disease Facts D0068 |
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Septoria Leaf Spot and Early Blight Host: Tomato Pathogens: Septoria lycopersici and Alternaria solani Signs/Symptoms: Spotting and eventual total collapse of leaves, working from the bottom of the plant up For more information see: UW Plant Disease Facts D0100/46 |
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Septoria Leaf Spot of Lilac Host: Lilac Pathogen: Septoria sp. Signs/Symptoms: Dead spots on leaves, potentially leading to complete leaf browning |
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Verticillium Wilt Hosts: Woody and herbaceous ornamentals, vegetables Pathogens: Verticillium sp. Signs/Symptoms: Wilting, branch dieback, plant death For more information see: UW Plant Disease Facts D0121/D0122 |
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Powdery Mildew Hosts: Herbaceous and woody ornamentals, fruit, vegetables, turf Pathogens: miscellaneous powdery mildew fungi Signs/Symptoms: Powdery white growth on leaves For more information see: UW Plant Disease Facts D0084/86/87 |
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Rhizosphaera Needle Cast Hosts: Colorado blue spruce, other spruces Pathogen: Rhizosphaera kalkhoffii Signs/Symptoms: Browning/purpling of interior needles of lower branches, followed by needle drop For more information see: UW Plant Disease Facts D0093 |
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Diplodia Shoot Blight and Canker Hosts: Austrian pine, other pines Pathogen: Diplodia spp. Signs/Symptoms: Dieback of brand tips with dead needles showing uneven lengths For more information see: UW Plant Disease Facts D0042 |
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Chlorosis Hosts: Pin oak, red maple, birch, azalea, white pine, blueberry Pathogen: None Signs/Symptoms: Yellow leaves with dark green veins For more information see: UW Plant Disease Facts D0030 |
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Improper Planting Hosts: Woody trees and shrubs Pathogen: None Signs/Symptoms: No root flare at the soil line, girdling roots, frost cracks, canopy thinning, early fall color, branch dieback, tree/shrub decline and death |
For more information on plant problems to watch for:
See https://pddc.wisc.edu/ or contact the University of Wisconsin Plant Disease Diagnostics Clinic (PDDC) at (608) 262-2863 or pddc@wisc.edu.
© 2022-2024 the Board of Regents of the University of Wisconsin System doing business as University of Wisconsin-Madison Division of Extension.
An EEO/Affirmative Action employer, University of Wisconsin-Madison Division of Extension provides equal opportunities in employment and programming, including Title IX and ADA requirements. This document can be provided in an alternative format by calling Brian Hudelson at (608) 262-2863 (711 for Wisconsin Relay).
Thanks to Diana Alfuth, Lisa Johnson and Carol Shirk for reviewing this document. Thanks also to David Clement (boxwood blight), Nancy Gregory-University of Maryland (lipstick rust), Amanda Gevens (late blight), and Marissa Wilmot (Septoria leaf spot of lilac) for use of their photos.
A complete inventory of UW Plant Disease Facts is available at the University of Wisconsin-Madison Plant Disease Diagnostics Clinic website: https://pddc.wisc.edu.
Submit additional lawn, landscape, and gardening questions at https://hort.extension.wisc.edu/ask-a-gardening-question/.