No, no, no Arlene -- the "Frozen Tundra" is ONLY in Green Bay!!
Welcome to ATP, AlexMac13 ! Like Greene (and others here), I'm not a professional -- just an avid gardener. I just wanted to add that there are lots of areas involving horticulture that you might pursue; one that I find quite exciting -- and which could really be a great thing for Detroit, in my opinion -- is making use of old unused buildings (like factories) for hydroponic growing of food crops in urban environments.
Otherwise, in terms of landscape design -- perhaps you can find an established designer to work with and learn what is actually involved; there's nothing like actually working at something to find out whether you want to take it to the next step.
I wish you great success in whatever you decide to pursue -- and I hope you'll stay around and let us know how things are going for you