List of rhododendron diseases explained

This article is a list of diseases of rhododendron (Rhododendron spp.).

Fungal diseases

Fungal diseases
Armillaria root rot Shoestring root rot	Armillaria mellea Rhizomorpha subcorticalis [anamorph]
Botryosphaeria dieback	Botryosphaeria dothidea Fusicoccum aesculi [anamorph]
Botrytis leaf and petal blight	Botrytis cinerea Botryotinia fuckeliana [teleomorph]
Bud and twig blight	Pycnostysanus azaleae Briosia azaleae
Cercospora leaf spot	Pseudocercospora handelii Cercospora handelii
Chrysomyxa leaf rust	Chrysomyxa ledi var. rhododendri Chrysomyxa piperiana Chrysomyxa roanensis
Clitocybe root rot (mushroom root rot)	Armillaria tabescens Clitocybe tabescens
Coryneum leaf spot	Seimatosporium rhododendri Coryneum rhododendri
Cryptostictis leaf spot	Seimatosporium mariae Cryptostictis mariae
Cylindrocarpon canker and wilt	Cylindrocarpon destructans Cylindrocarpon radicicola
Damping-off, Pythium	Pythium spp.
Damping-off, Rhizoctonia	Rhizoctonia solani Thanatephorus cucumeris [teleomorph]
Exobasidium leaf spot	Exobasidium burtii
Glomerella canker and dieback	Glomerella cingulata Colletotrichum gloeosporioides [anamorph]
Gray blight	Pestalotia sydowiana
Leaf and flower gall	Exobasidium vaccinii Exobasidium azaleae
Lophodermium leaf spot	Lophodermium schweinitzii
Ovulinia petal blight	Ovulinia azaleae Ovulitis azaleae [anamorph]
Pestalosphaeria leaf spot	Pestalosphaeria concentrica Pestalotiopsis guepini [anamorph]
Pestalotia leaf spot	Pestalotiopsis sydowiana Pestalotia rhododendri
Phymatotrichum root rot (cotton root rot)	Phymatotrichopsis omnivora Phymatotrichum omnivorum
Phytophthora dieback	Phytophthora nicotianae var. parasitica Phytophthora parasitica Phytophthora cactorum Phytophthora cinnamomi Phytophthora citricola Phytophthora citrophthora Phytophthora heveae Phytophthora lateralis
Phytophthora root rot	Phytophthora cactorum Phytophthora cinnamomi Phytophthora citricola
Powdery mildew	Microsphaera vaccinii Microsphaera penicillata var. vaccinii
Pucciniastrum leaf rust	Pucciniastrum vaccinii
Septoria leaf spot	Septoria rhododendri
Spot anthracnose	Sphaceloma sp.
Stem canker	Cylindrocladium theae Calonectria theae [teleomorph]
Witches' broom	Exobasidium vaccinii-uliginosi

Nematodes, parasitic

Nematodes, parasitic
Dagger, American	Xiphinema americanum
Lance	Hoplalaimus galeatus
Sheath	Hemicycliophora spp.
Spiral	Helicotylenchus erythinae
Stubby-root	Paratrichodorus spp.
Stunt	Tylenchorhynchus claytoni

References

• Common Names of Diseases, The American Phytopathological Society
• Diseases and pests of rhododendrons
• Images of diseases and pests of rhododendrons