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Arborvitae disease #938322

Asked July 07, 2026, 10:52 AM EDT

Please help me identify this and find a cure.

Hennepin County Minnesota

Expert Response

Thank you for writing.

That appears to be tip dieback, from a fungus. https://purduelandscapereport.org/article/arborvitae-needle-blight/

It is more common when plants are crowded or damp. The solution is pruning, not fungicides.
https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/needlecasts/pestalotiopsis-tip

Steve Miles, Master Gardener, Hennepin County, (I am a volunteer human being: not a bot, not AI). I'm an avid gardener but not a degreed or certified horticulturist or arborist. I will do much better if you also send a photograph. I like follow-up questions. The University' garden soil tests are excellent. https://soiltest.cfans.umn.edu/testing-services/lawn-garden This is how to find a tree expert. https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional A Directory of ISA certified arborists is at https://certificates.directory.isa-arbor.com/ The Minnesota Landscape Arboretum is a wonderful place to see and learn about plants that grow in Minnesota. https://mngardens.horticulture.umn.edu/minnesota-landscape-arboretum Ask a Master Gardener is a public service of the University of MInnesota's Extension Division. Please donate if we make you happy. https://give.umn.edu/gardener Replied July 07, 2026, 12:52 PM EDT

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This work is supported in part by New Technologies for Ag Extension grant no. 2020-41595-30123 from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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