Wash flowers and shake dry. Bring sugar and 400 ml water to the boil, remove the pot from the heat and add the flowers. Stir so that all petals are covered with syrup. Cover the pot and leave it in a cool place for about 3 days. Pour the syrup through a fine sieve and immediately pour into a clean, hot rinsed and tightly closed bottle. Tastes great with Prosecco or mineral water.