By completing the quest "There stands the Grass" you are unable to deliver a package to "Dr. Hilden" in Camp Mccarren which is the first requirement for the quest
"You can depend on me".
Unable to complete that portion of the quest, you cannot unlock the companion Cass, which locks you out of completing the quests "Heartache by the number" and "Birds of a feather", as well as the achievement/trophy for getting all the companions.
Simply adding a new dialog to Dr. Hilden to accept the package after the completion of "There stands the grass" would fix this.