Evanston Now City lacks data to support restrictive tree ordinance Evanston aldermen are scheduled Monday to consider a tree ordinance amendment that would impose hundreds of thousands of dollars in new costs annually on homeowners. An aerial view of Evanston showing variations in the tree canopy. (Google Maps) Evanston aldermen are scheduled Monday to consider a tree ordinance amendment that would impose hundreds of thousands of dollars in new costs annually on homeowners. The goal of the ordinance ostensibly would be to protect trees on private property. But in response to an inquiry from Evanston Now, city officials conceded that they have conducted no studies to determine whether the extent of the city’s tree canopy is increasing or decreasing.