Connecticut State The Connecticut Agricultural Experiment Station

Woody Ornamental Diseases

Plant Disease Information Office logo

Return to PDIO

Woody Ornamental Disease Image Gallery

This gallery contains images of common plant disease problems which occur in Connecticut. Clicking the link below an image will open a fact sheet which explains the disease and options for management.

Amelanchier rust on stems with fungal fruiting structure on them       Amelanchier rust on fruits with orange fungal growth on them

                                            Amelanchier Rust                            

Amelanchier powdery mildew       Anthomeda Botryosphaeria canker

  Amelanchier Powdery Mildew           Andromeda Botryosphaeria Canker

Apple fire blight with brown stem tissues       Apple fungal leaf spot

   Apple Fire Blight                                Apple Fungal Leaf Spot

 Apple Botryosphaeria canker       Apple rust with yellwo spots on leaves

       Apple Botryosphaeria Canker                         Apple Cedar-apple Rust             

     Apple scab with black fungal growth on the upper surface of leaves       Ash rust with orange sporulation on leaves    

    Apple Scab                                                 Ash Leaf Rust         

    Azalea leaf gall with white mold on the surface       Beech anthracnose with brown lesions along veins    

       Azalea Leaf Gall                                 Beech Anthracnose

     Beech leaf disease with dark green bands on leaves       beech leaf disease with yellowing of leaf tissues between veins

Beech Leaf Disease

    Birch fungal leaf spot       Boxowod black root rot

                                      Birch Anthracnose                          Boxwood Black Root Rot                  

Boxwood blight    Boxwood edema

 Boxwood Blight                          Boxwood Edema

        macrophoma leaf spot of boxwood wiht brown leaves and black fungal fruiting bodies on them             Volutella blight of boxwood wiht brown leaves and orange sporulation on them

        Boxwood Macrophoma Leaf Spot                   Boxwood Volutella Canker    

   Browning of leaves on boxwood bushes caused by winter injury        phytophthora root rot of butterfly bush

                       Boxwood Winter Injury                 Butterfly bush Phytophthora root rot        

     Brown rot of cherry tree with dead twigs     Brown rot of cherry tree with dead twigs

       Cherry Brown Rot                     

Balck know of cherry with black fungal structures on a stem    Black knot fungal strutures on a cherry tree in the winter

 Cherry Black Knot

   cherry fungal leaf spot with brown spots and hole on leaves   Cherry fungal leaf spot wiht fallen leaves on a deck

                   Cherry Fungal Leaf Spot

Dogwood anthracnose on leaves with brown spots on them    Dogwood anthracnose with brown spots on leaves

Dogwood Anthracnose 

   anthracnose on red twig dogwood with small brown spots on leaves     powdery mildew of dogwood wiht distorted new leaves and white mildew on leaves

Dogwood (Red-twig) Anthracnose                   Dogwood Powdery Mildew

  Dutch elm disease with discoloration of vascular tissues     Dutch elm disease with of wilting of leaves and declining of the tree

          Dutch Elm Disease

fungal leaf spot of elm with yellow spots on leaves      fungal leaf spot of elm with yellowing of leaves on a elm tree

Elm Stegophora Leaf Spot

Enkianthus anthracnose with brown lesions on leaves     Eastern filbert blight with fungal fruiting structures on a stem

                                     Enkianthus Anthracnose                 Filbert Eastern Filbert Blight                                            

PHytophthora root rot of forsythia bush in a pot     Anthracnose of hawthorne with brown spots on leaves

Forsythia Phytophthora root rot                     Hawthorn Anthracnose 

Hawthorn rust with orange fungal fruiting structure on stems    Hawthorn rust with orange fungal fruiting structure on fruits

Hawthorn Rust

Entomosporium leaf spot of hawthorn with brown lesions on a leaf     Phytophthora root rot of heather bush in a pot

Hawthorn Entomosporium Leaf Spot            Heather Phytophthora Root Rot

Downy leaf spot of hickory with yellow spots on the upper leaf surface and white mildew on the lower surface of leaves    Gnomonia leaf spot of hickory with brown spots on leaves  

Hickory Downy Leaf Spot              Hickory Gnomonia Leaf Spot

winter injury on holly with leaf scorch at the edge of leaves     fungal leaf spot of holly with gray spots and black fungal fruiting bodies on leaves

                   Holly Winter Injury                                   Holly Phyllosticta Leaf Spot  

 fungal leaf spot of honey locust with brown spots on leaves    horsechestnut leaf blotch with brown lesions on leaves

      Honey Locust Cercospora Leaf Spot              Horse Chestnut Leaf Blotch   

 Botryosphaeria canker of hornbeam      anthracnose of hornbeam with brown spots on leaves

Hornbeam Botryosphaeria Canker                            Hornbeam Anthracnose

 powdery mildew of hornbeam     Bacterial leaf spot of hydrangea

        Hornbeam Powdery Mildew                      Hydrangea Bacterial Leaf Spot

Cercospora leaf spot of hydrangea     Powdery mildew of hydarngea

Hydrangea Cercospora Leaf Spot              Hydrangea Powdery Mildew

         Phyllosticta leaf spot on a leucothoe leaf with reddish brown spots and gray center   Powdery mildew on leucothoe leaves with reddish brown patches          

     Leucothoe Phyllosticta Leaf Spot                       Leucothoe Powdery Mildew    

Bacterial blight of lilac with collapsed new shoots      powdery mildew of lilac with white mildew on the upper surface of leaves

Lilac Bacterial Blight                                Lilac Powdery Mildew   

Phytophthora root rot of lilac bushes from pots      fungal leaf spot of lilac with brown spots on leaves

Lilac Phytophthora Root Rot                         Lilac Septoria Leaf Spot

 Powdery mildew of magnolia with white mildew on leaves      maple anthracnose with brown spots on leaves

Magnolia Powdery Mildew                                Maple Anthracnose

Tar spot of maple with black spots on a leaf    Botryosphaeria canker of Japanese maple with black fungal fruiting bodies on the stem

                     Maple Tar Spot                                      Maple Botryosphaeria Canker

     Phyllosticta leaf spot of maple with small brown spots on a leaf   Powdery mildew of maple with distorted new leaves and white mildew on the surface

Maple Phyllosticta Leaf Spot              Maple Powdery Mildew 

    Septoria leaf spot of maple with small brown spots on a leaf   Verticillum wilt of maple with discoloration of vascular tissues

        Maple Septoria Leaf Spot                         Maple Verticillium Wilt               

          fungal leaf spot of mountain laurel with brown spots and gray center on leaves       powdery mildew of ninebark bushes with distorted leaves and white mildew on the surface

                   Mountain Laurel Leaf Spot                    Ninebark Powdery Mildew

        Oak anthracnose with brown lesions on leaves      Botryosphaeria canker of oak with diebacks

                 Oak Anthracnose                                 Oak Botryosphaeria Canker

       leaf blister of oak with light brown lesions on leaves     Tubakia leaf spot of oak with large brown lesions on leaves

                    Oak Leaf Blister                                          Oak Tubakia Leaf Spot          

        powdery mildew of oak with white mildew on the lowder surface of a leaf   Febraea leaf spot of pear with brown spots on a leaf

       Oak Powdery Mildew                 Pear Febraea Leaf Spot

        Trillis rust of pear withe reddish brown spots on leaves    Trellis rust of pear with necrosis and drying of leaves

Pear Trellis Rust 

     Powdery mildew of pear with white mildew on the lower surface of leaves white mildew on     pear scab with black mold on the surface of a leaf

Pear Powdery Mildew                               Pear Scab

  Black knot on a plum stem     black knots on a plum tree

            Plum Black Knot

 fungal leaf spot of rhododendron with brown spots on leaves

Rhododendron Fungal Leaf Spot

Alternaria leaf spot of privet with brown spots on leaves    Cercospora leaf spot of privet with brown spots and gray center on leaves

Privet Alternaria Leaf Spot       Privet Cercospora Leaf Spot

White Exobasidium leaf galls on a rhododendron shoot     winter injury on rhododendron bushes with browing and drooping of leaves

  Rhododendron Leaf Gall             Rhododendron Winter Injury  

      Phytophthora root rot of rhododendron with wilting of leaves     Black spot of rose with black spots on leaves 

Rhododendron Phytophthora root rot                            Rose Black Spot

       Bramd canker on a rose stem      Downy mildew of rose with reddish brown lesions on leaves

                  Rose Brand Canker                          Rose Downy Mildew

    powdery mildew of rose with white molde on leaves and stems    rose rust with orange sporulation on the lower surface of leaves

                            Rose Powdery Mildew                                   Rose Rust        

   powdery mildew of sycamore with distorted new leaves and white mildew on the surface      Powdery mildew of winterberry with white mildew on the surface of leaves

       Sycamore Powdery Mildew                      Winterberry Powdery Mildew

   Return to the Top