Hosts
Many plants - especially arborvitae grown too close together
Usually, Pestalotiopsis sp. killed foliage is near the base of the plant and where foliage is relatively dense. The disease usually starts at the tip of the foliage and progresses towards the leaf base. The color of the foliage goes from green to yellowish, then to a dark brown that can look almost black. The disease may kill the smaller twigs where the infected needles died.
Written by James Schuster, Extension Specialist, Horticulture and Plant Pathology, University of Illinois at Urbana-Champaign.