Arborvitae diseases are diseases that affect the arborvitae tree, an evergreen with scale-like leaves. Some common arborvitae diseases are Kabatina twig blight, Pestalotiopsis tip blight and Phomopsis twig blight. All of these diseases can be treated with fungicides or barriers that protect the tree.Continue Reading
A clear sign of Kabatina twig blight is ashy or gray tips in young branches. Older, larger branches may be affected also, and where the dead wood meets the uninfected part, small, pimple-shaped fruiting structures are present. As treatment, infected twigs and branches must be pruned, and the fungicide mancozeb should be applied to protect the foliage.
Pestalotiopsis tip blight is marked by twigs turning tan to brown with pimple-shaped fruiting structures present on their surface. To treat this, the trees need to be protected from winter injury, drought and other possible harm. Copper should be applied to protect the foliage.
Kabatina twig blight and Phomopsis twig blight can affect the same tree simultaneously. The latter is marked by dying branches that remain on the tree for many months. As with other arborvitae diseases, pimple-shaped fruiting structures appear where the dead wood and the not-yet-infected wood of the branches meet. Infected twigs and branches should be pruned and destroyed, and the fungicide thiophanate-methyl should be applied when new growth is present.Learn more about Trees & Bushes