Drainage ditches and what to plant there

Hello Good Folks,

I am a teacher at the high school level and involved in the ecoteam which is comprised of students and teachers who work on projects throughout the year.
Really it has turned into a gardening/greenhouse club.  Students are curious about growing things, it's great.

We are pairing with the local township to plant trees around the municipal ditches. Wondering if someone has something unique to suggest that is permaculture in nature.  Native species for sure but what else can be done?  The area is southern Ontario, zone 7b, near Detroit, tucked in the southern part of the Great Lakes.  

Just putting it out there.

Thank you,

Aaron

How tall and wide of a tree is acceptable without interfering with the ditch itself, utilities, walkways etc?  Is it a residential, business or a more rural or park like situation?  I would guess hard mast, soft mast and berry producing trees and shrubs which would benefit wildlife and be used by people as well.  Oaks, pecan, hickory, hazelnut, apples, crabapples, pears, american plum, nannyberry, serviceberry, elderberry and the list goes on.  Variety is the spice of life.  

The one concern I would have is if you are more rural and have deer in the area.  Using cages or tubes to protect young trees from browse can be as expensive as the plants themselves.  Having kids involved in the community is awesome.  They will remember what and where they planted until they are old and grey.