Is it a fungal problem? Learn to identify common fungal diseases in plants and discover effective organic and conventional treatment methods.
Brown spots about a quarter inch across, ringed in purple or black, on your boxwood or hydrangea leaves are most likely Phyllosticta leaf spot. Here is the honest news first: on established shrubs this fungal disease is cosmetic, and a…
Fusarium root rot treatment begins with a fact most guides bury at the bottom of the page: there is no cure for an infected plant. Once Fusarium oxysporum colonizes a plant’s water pipes, no spray, drench, or home remedy removes…
Gray spots about a quarter inch across on your St. Augustine grass are usually gray leaf spot, a fungal disease that explodes when daytime temperatures sit between 80 and 90 F with humid nights above 65 F. The short version…
You can keep Rhizoctonia out of your seedlings and transplants, but you cannot sterilize your garden against it. That is the honest starting point. The fungus behind rhizoctonia root rot survives for more than 3 years in soil as tiny…
Rhizoctonia root rot is treatable, but only if you catch it early and fix the conditions that invited it. The pathogen is Rhizoctonia solani, a soilborne fungus that attacks seedlings, houseplants, vegetables, and lawns at or just below the soil…
You find the gray fuzz on a Monday morning, coating a dying blossom at the bottom of your tomato plant like ash. By Friday it has crept 12 inches up the stem, and one fruit wears a ring of pale…
Cottony blight is the common name for Pythium blight, a fast-moving fungal disease that can turn a healthy lawn into a greasy, matted mess within a day or two of hot, humid weather. If you have noticed circular patches of…
Coryneum fruit spot is the fruit-stage symptom of Coryneum blight, a fungal disease that also goes by shot hole disease, and it covers peaches, apricots, and other stone fruit with small purplish spots that turn scabby, gummy, and disfigured before…
Corticium blight is an older name still used for two related fungal problems, pink disease and thread blight, that wrap twigs and leaves in fine fungal threads and slowly girdle branches on trees like fig, citrus, coffee, and pepper. If…
Coniothyrium canker and dieback is one of the most common reasons a healthy-looking rose cane turns brown and dies from the tip down, often within a single growing season. If you already spend time pruning your roses each spring, this…
Coniothyrium leaf spot is a fungal disease best known for scarring yucca leaves with sunken brown lesions, though the same genus of fungi causes similar leaf spots on agave, dracaena, and a range of other landscape and houseplants. If you…
Constriction canker is a fungal disease of peach twigs and buds caused by Phomopsis amygdali (synonym Fusicoccum amygdali), named for the way small cankers form around leaf scars and slowly constrict, or girdle, the twig until it dies. It is…
Copper spot is a summer turfgrass disease that covers susceptible grass with small, circular, copper-colored patches, most noticeable right after a fresh cut. If copper spot shows up on your lawn, understanding what makes it worse will help more than…
Corm rot is a general term for several fungal diseases that turn the underground storage structure of plants like gladiolus, crocus, saffron, and taro soft, discolored, and unable to sprout. If a corm rot problem is destroying your bulb-like plantings,…
Common smut is one of the most recognizable diseases a home gardener or field grower will ever see on corn, because there is no mistaking a swollen, silvery gall bursting open into a cloud of black powder. If you are…
Colletotrichum is best known for the leaf spot form of anthracnose, but the same fungal genus can also attack stems, shoots, and crowns directly. This form shows up as sunken cankers, dieback of shoot tips, and internal browning at the…
Colletotrichum leaf spot is a fungal disease caused by species in the genus Colletotrichum, the same group of fungi responsible for anthracnose on trees, shrubs, vegetables, and turf. It shows up as small, sunken spots with distinct borders, and on…
A plant that suddenly wilts and dies even though the soil looks fine and the roots seem intact often has a problem hiding right at the surface, where the stem meets the soil. That narrow band is called the collar,…
A tree or shrub that suddenly declines, loses limbs, or fails to leaf out in spring often gets blamed on drought, winter injury, or old age. Sometimes the real cause is underground and has been there for years: Clitocybe root…
A clematis that goes from lush and flowering to black and collapsed within a few days is alarming enough that most gardeners assume the worst. The good news is that clematis wilt, despite the dramatic collapse, is rarely fatal to…
