Pick the flowers on a dry day. Possibly put on gloves, otherwise the fingers will turn yellow. Pluck flowers - everything GREEN that gives off milk has to go!
Boil 1 liter of water, the sliced lemons and flower petals for 30 minutes. Press the brew through a cloth (clean Molton diaper). Cook slowly with sugar for 1 hour. Caution - can boil over !!! Make a gel test! Use a large saucepan and repeatedly wash the inside edge with cold water (and a brush).
TIP: For a cough honey: 1 glass of dandelion honey, 2 cloves, 2 handfuls of dandelion blossoms (again without green), 1 cinnamon stick, mix everything well. Leave to rest in the sun for 2 weeks and fill into glasses again. Secret recipe of my great-grandmother!