As I remember (circa 1989), Ferndale was one of the well to do areas of Detroit. Of course, you'll need to do a lot of homework before taking the big plunge. Definitely talk to landscape design professionals. Have all your ducks in a row, so you can ask meaningful questions that you won't take up a lot of their time. Unless someone responds here that is in the profession, take our advice as such. As Growitall says, there are a lot of nit-wits out there who call themselves professionals, and turn out great designs on paper, but when it comes to actual implementation, fall short because of a lack of knowledge of live materials.
Horticulture therapy has been in practice for decades, but really, that neither here nor there. It's a very good thing.
