Bring the sugar, water and lavender to a boil in a pan over high heat. Stir until the sugar is dissolved, and allow to fully cool. You can refrigerate this to speed up the process, or do this the night before.

Add the lemon juice and sparkling water to the sugar syrup and mix together. If you find that it is too sweet, you can add up to 2 more cups of sparkling water or regular water.

Refrigerate until chilled, then strain to remove the dried lavender. Pour into glasses and top with a sprig of lavender.