Spargelbesen - Besenwirtschaft

Have you ever heard of a Besenwirtschaft or Spargelbesen? 
It is a temporary tavern/bar opened only at a certain period of time is called a Besen (broomstick) here in Stuttgart.
Serving seasonal food or the first wine in autumn.
Usually it all takes place in a home, barn or basement, spare room or even garage converted for the occasion for wining and dining. Meanwhile there are also Besen, who are more like restaurants, but again only open during a certain period of time.
Some locations are featuring a broomstick above their doors or on their buildings.
How to locate them: www.besentermine.de