Arborvitae One-Sided Browning: Environmental Diagnosis Needed

Likely Environmental

Brown tips low on one side + sap globs on twig tips + gutter overflow = root zone issue (waterlogging one side?) or chemical exposure (runoff?). Not typical disease/insect.

Info Needed for Diagnosis

• Photos: whole plant showing brown side, close-up of twig tips.
• Planting age.
• Any sprays/applications nearby.
• Has brown area expanded?

Common Causes

• Root suffocation from saturated soil.
• De-icing salt runoff.
• Herbicide drift.