Starting mid-May in Bratislava and the south, and progressively later in the rest of the country, large bushes with flat white flower heads are in bloom. These are black elder bushes, which later on will develop clusters of dark blue-purple berries. The white flower heads have a strong fragrance, and that scent translates into a delicious syrup to mix with water for a refreshing drink.
There is still time to catch the last of the flowers if you pick them now. Before you look for elderflowers, however, make sure to acquaint yourself with what the plant looks like so you can be sure to identify it correctly. Also, try to collect flowers that haven't been rained on, as it is the pollen that gives the syrup its taste and yellow colour.