Chestnut Blight in Delaware
CRITICALFungus
Chestnut Blight is currently active in Delaware. Watch your susceptible trees closely and act early.
About Chestnut Blight
A fungal disease that functionally eliminated the American chestnut as a canopy tree species in eastern forests by the mid-20th century. Once numbering in the billions, mature American chestnuts are now exceedingly rare. Root sprouts survive but are re-infected.
Symptoms to watch for
Sunken orange-brown cankers on bark, yellowish-orange fungal fruiting bodies on cankers, wilting of foliage above canker, sprouting below canker, bark splitting around canker margins
Trees at risk in Delaware
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Treatment options
Hypovirulence Biological Control
Introduction of a virus (Cryphonectria hypovirus) that weakens the blight fungus, allowing trees to compartmentalize cankers. Has shown success in Europe but limited efficacy in North American forests due to fungal diversity.
Backcross Breeding Programs
The American Chestnut Foundation's breeding program crosses American chestnuts with blight-resistant Chinese chestnuts, then backcrosses to recover American traits. Producing potentially blight-resistant trees for restoration planting.
Recommended Products & Tools
Helpful supplies for managing Chestnut Blight. Always read and follow label directions, and confirm a diagnosis before treating.
Broad-spectrum protectant for many fungal leaf and bark diseases.
Preventive spray for needle cast, leaf spots, and blights.
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Browse all Delaware arborists →Frequently asked questions
Is Chestnut Blight in Delaware?
Chestnut Blight is currently active in Delaware. Watch your susceptible trees closely and act early.
What does Chestnut Blight look like?
Sunken orange-brown cankers on bark, yellowish-orange fungal fruiting bodies on cankers, wilting of foliage above canker, sprouting below canker, bark splitting around canker margins
What trees does Chestnut Blight affect in Delaware?
It affects American Chestnut. Susceptibility varies by species.
How do I treat Chestnut Blight?
Options include: Hypovirulence Biological Control, Backcross Breeding Programs. Confirm the diagnosis before treating, and consider a certified arborist for high-value trees.