Shel's first wife, Susan Taylor Hastings, died suddenly one day before his daughter's fifth birthday. While he never settled down to build a family, Susan was still a key element in his personal development and deserves some character exploration. Anna Friel (Pushing Daisies, Limitless) would be well-suited for the role. While we can't see her carrying a film as its leading lady, she would definitely make a striking and evanescent figure for Silverstein's short-lived first marriage.
Out of his relationship with Susan came Silverstein's first daughter, Shoshanna Jordan Hastings. After her mother's death, Shoshanna departed to live with her aunt and uncle rather than her nomadic father. And at age 11, she died suddenly of a cerebral aneurysm. It is reported that Silverstein often wished he had been a better father to her, and he dedicated A Light in the Attic "to Shanna." In Mad Men, Kiernan Shipka plays a similarly neglected daughter as Sally Draper - misunderstood by her mother and often overlooked by her father. She's got an endearing slight lisp and doll-like features and would suit the role of Shoshanna towards the end of her life quite perfectly.
Silverstein never married again after Susan's death, but he eventually settled down in Florida with Sarah Spencer. We think Elizabeth Banks (The Hunger Games, Seabiscuit) would make a great addition to the cast as Shel's second baby-mama. She has the all-American beauty of a woman to attract a man who surrounded himself with Playboy bunnies and had a reputation of something of a womanizer, and we suspect she can also channel the gumption of a woman who made her living driving the conch train in Key West.
Perhaps the only thing more recognizable than his cover illustration of the Giving Tree dropping an apple into the awaiting hands of a child is Shel Silverstein's cueball-bald skull and full, dark beard. His portrait graces the back of each of his poetry collections, creating a daunting challenge for the casting directors of the adaptation. We think that a bald-headed, bearded Adrien Brody would fit the bill quite nicely. He's got the nose, hooded eyes and, more importantly, the brooding, introspective aura of any great artist.
It's always difficult to cast larger-than-life characters, especially when they're still alive. For this reason, we'd tap Hugh Hefner to play his younger self— Hugh Hefner personally handed Silverstein his first paycheck for the Playboy comics, giving him his big break in media (Shel later went on to write a recurring travelogue for the magazine). He hasn't much aged in 30 years (the miracles of modern medicine), so maybe it won't be too great of a stretch.
Towards the end of his life, Shel turned towards his new family - steady girlfriend Sarah and son Matt. As with A Light in the Attic for Shoshanna, Silverstein dedicated Falling Up to Matt. We loved Liam Jones in The Way Way Back and think he could tackle a few more child roles before he outgrows them.