City opinion on trees
I spoke with Mike Zapata of the City of Wylie Code Enforcement Department today. He stated that there is no ordiance prohibiting the planting of trees in the city easement area between the curb and sidewalk, but they do not recommend it.
Since our driveways are front-loaded our utilities are in this area, and the planting of trees there could lead to damage that we would be responsible for paying to repair. Also, many of the trees that would provide the best coverage in the long term would not fit into the size of the area we have along our streets and would then damage the sidewalks.
I can not see the HOA undertaking this huge responsibility, but if an individual Homeowner chooses to plant a tree on your property in the easement you may do so.