“Osem” means eight in Slovenian and it’s the root of the word “Osmiza”. Eight is the number of days, as decreed by Joseph II of Hapsburg in the late 1700s, in which farmers were allowed to sell their wares directly to the public. The tradition was born as a way for farmers to get rid of their surplus. There is no set time of year, but typically, they flourish in the summer but you can also find some open even in the winter. The length they can stay open is calculated on the quantity of wine they’ve produced. So the minimum is 8 days however some open more times (8 days each time) in one year to sell everything from eggs and fresh seasonal fruits and veggies to various cured meats and wines.
The Osmiza (sometimes also spelled Osmizza or Osmica) owners signify they are open to the public by hanging a small bunch of tree greens or ivy outside their farmhouses and along the roadside. Sometimes you will see random ones with a little wooden flag pointing the way, other times you’ll actually see a sign. With all the lush vegetation in the Carso, this signage is sometimes hard to see or recognize!
The best way to be sure however, is to follow the local blogs and social media sites that are kept fairly up to date.