Establish and maintain a safe and sustainable tree resource in the park system and oversee various City ordinances that apply to trees. Property owners are responsible for the care and maintenance of street trees located in the boulevard abutting their property; this includes keeping them properly trimmed. A free tree trimming guide and other information about trimming and planting street trees is available on website. See this year's list of licensed tree trimming arborists along the left hand side of website People with questions regarding EAB (Emerald Ash Borer) can find a list of FAQ's, a video, a list of licensed arborists and city approved replacement trees at website.