To keep your employees in the dark, and every now and then throw shit on them.
A management philosophy prescribing to the theory that to best motivate your employees, you must at all times:
1. Keep them in the dark.
2. Feed them full of shit.
This form of management applies to every situation where management is involved. Be it passing on critical information to employees, or informing people of policy change and company announcements. The entire purpose is to be as vague and unresponsive as possible. The ultimate culmination and success of this management style can be found when people draw comparisons to management and a black hole. Where resources and information go in and nothing comes out.
Example of Mushroom Management:
Employee1: So you talked to management on our companies re-bid for the contract?
Employee2: Yea, but didn't get much. Management said there's nothing to report.
Employee3: How can that be? Our fucking contract is up next month, how can they not know anything?
Employee1: Don't ask me dude. Man I feel like I'm constantly in the dark and fed full of shit. Kind of like a mushroom.
1. Mushroom Management
Restrict employee access to information and decisions (keep them in the dark).
When information is conveyed, it is incomplete, inaccurate, or full of marketing hyperbole (throw shit on them).
Large, hierarchical, process-bound organizations are frequently guilty of the most egregious forms of "mushroom management."