Kazanlak's Rose Festival takes over the town for a long weekend in early June, at the peak of the harvest. The events spread across several days and several venues: a ritual rose-picking at sunrise in one of the village fields, the crowning of the Rose Queen, a colourful parade through Kazanlak's streets, folk music and dance performances, and an opening of the distilleries to the public.
The festival is genuine — it is a community celebration that happens whether or not tourists come — but it has become well-known enough that hotels in Kazanlak fill up months in advance. If you want to be here for it, book accommodation by early spring. The exact dates change each year depending on the harvest; check the Kazanlak municipality website closer to the time.