Dogwood anthracnose: what the extension services record

This page reports what the official source says. It is not legal advice: ask the office named here. It does not identify what is wrong with any tree and does not say what should be done about one. None of the four pages read lists dogwood anthracnose as regulated or notifiable. Each section names its source, all read on October 9, 2026. The full list of diseases is on the tree diseases page.

Cause and origin

NRCan, New Hampshire and West Virginia University name the fungus Discula destructiva, and Maryland calls it Discula. Natural Resources Canada, called NRCan, says the origin of the disease is unknown but widely considered to be exotic. It says the disease was first reported in the United States in 1978, was confirmed in Ontario in 1998, and that the same agent was found in 2003 in a nursery in Lombardy, Italy, and in a private garden in Germany. Its distribution list names British Columbia and Ontario and notes that the disease is being eradicated in Ontario. West Virginia University Extension says the fungus reached eastern North America from Asia by accident in the late 1970s and spread fast, decimating natural populations of flowering dogwood in southern New England, and that because it is non-native the flowering dogwood has no natural defense against it. The University of New Hampshire says the first New Hampshire cases were confirmed in June 1990 at its Plant Diagnostic Lab.

Hosts

Dogwood	What is recorded	Source
Flowering dogwood	Cornus florida: all varieties are susceptible; NRCan lists it among the two species seriously damaged in natural habitats	NRCan, West Virginia University
Pacific dogwood	Cornus nuttallii: susceptible; blighting of terminal leaves in fall is common, which West Virginia University says reduces spring budbreak	NRCan, West Virginia University
Kousa dogwood	Cornus kousa: described as tolerant by New Hampshire and relatively resistant by West Virginia University	University of New Hampshire, West Virginia University
Other dogwoods	Cornelian cherry (C. mas) is named as a possible substitute by New Hampshire, and as resistant by Maryland and West Virginia University; Tartarian (C. alba) and red osier (C. sericea) are named as resistant by Maryland and West Virginia University; alternate-leaf (C. alternifolia) and silky (C. amomum) are called relatively resistant by West Virginia University	University of New Hampshire, University of Maryland, West Virginia University

Signs the sources list

NRCan calls it a foliar disease. Initial symptoms are on leaves in the lower crown, moving upward, and leaves in shaded or very damp spots are infected first. Tan spots, often with a purple border, run together into large blotches; the spots may fall out, leaving shot holes. Heavily infected leaves may drop early or hang on the twigs long after normal leaf fall. Maryland gives the start of symptoms as mid to late May, and says the underside of the leaf shows many small tan to brown dots about the size of a printed period, the source of the spores.

From the leaves the infection moves to twigs, buds and fruit, and then to larger branches. New Hampshire says cankers develop from leaf nodes, dead twigs appear tan with black pin-point fruiting bodies, which release orange spore masses in wet weather, and water sprouts may form on the trunk as a result of twig dieback. West Virginia University adds that the white bracts at flowering can be infected. Maryland says young green stems and water sprouts are especially susceptible and that the wood under the bark of older branches looks dark brown.

How it spreads and persists

West Virginia University says the fungus persists as cankers on trunks and branches, and in twigs and dead leaves as blister-like fruiting structures. In spring, rain splashes the spores onto newly expanded leaves, flowers and soft tissue, and infection starts on the lower branches first. It says short-range spread is by rain splash and long-range spread is usually by insects, birds or contact with infected plants. Maryland also says the disease overwinters in twig and stem cankers and that spores are carried by rain, dew or insects. NRCan says infection is most likely in cool, wet weather in spring and fall, though it can occur any time in the growing season, and that drought and winter injury appear to raise susceptibility.

Harm to the tree

NRCan says dogwoods of every size can die, with young seedlings and forest understory trees hit hardest. It reports a mortality rate of 46 percent at an ecological monitoring site in Ontario from 1995 to 2000. New Hampshire says that if conditions favoring spread persist, the entire tree may die in two to three years. West Virginia University says multiple cankers can girdle individual branches or kill the whole tree once it is severely weakened. Maryland says that dogwood anthracnose was once the most serious disease of dogwoods in landscapes and forests and is less common, with powdery mildew the most serious disease of dogwood.

Regulated status and reporting

None of the four pages names a regulation, quarantine order or report line for dogwood anthracnose. For the agencies that take reports of regulated pests, see the guides on reporting a pest in Canada and the United States. For the host species, see flowering dogwood.

Management as the sources list it

New Hampshire and Maryland both describe cultural steps, a fungicide program and the use of resistant dogwoods, and West Virginia University describes the same and says fungicide reduces new infections but does not cure existing ones. This page gives no product names, rates or timings. For who may apply pesticides, see pesticide licences.