This is the Foster City Tree Inventory from 2000. Foster City has seen many trees die recently. Why? Many trees are non native and they haven’t thrived. Also many trees have slowly failed. Did you know Foster City’s salt water table is only a few feet deep? So trees that have deep roots don’t thrive in Foster City due to the salt water. YET, trees with shallow roots infiltrate pipes, homes, and do damage to streets and crosswalks. It is a careful balance.