Shade tree mechanic is an individual who isn’t certified enough to repair motorized vehicles. This term and/or title carries a lot of prejudice and opinions with it though.
A “Shade tree mechanic” uses methods that are not “by the book” and doesn’t use proper tools, just a baling wire with some duct tape.
It is used as a joke to a person who does more damage to the car than fixing it. But some people think a “Shade tree mechanic” is more like a person who can come up with splendid solutions using their own creativity.
The term is kind of literal in a way. They call the amateur mechanics “Shade tree mechanics” because they are fixing their personal vehicles under the shade of a tree in their backyard instead in a proper garage.
This expression was mainly used in the 70s until cars didn’t have a more complex system and didn’t require regular maintenance, better tools and technology.
Back then these men had their good old toolbox, a set of wrenches, a buddy with them and a couple of beers to spend a casual afternoon fixing their car.
Therefore, almost every neighbourhood had their own handy “Shade tree mechanic”.
For decades now, every neighbourhood had their local “Shade tree mechanic”.
This term became popular around the 60s and 70s probably, but there isn’t a set time for when it happened.
First definition on Urban Dictionary for the term was written in 2006.