Means that you use a tree or a bush as an
umbrella.
Basically because you're too damn mean to buy one. You can also make it a little more
realistic by non-watering it, so it would become yellow.
Alejandro: Hey Sha, forecast says
it's going to be really HOT this summer. Are you buying an
umbrella for the yard?
Shayan: God NO! I've just kept my tree with no water during all the spring so now it is yellow dry Eco-friendly Umbrella and I can use it to sit in
the shade!