In a small saucepan stir together the sugar, lemon zest, verbena and 1 cup of water. Place over medium heat, bring to a boil and then reduce the heat and let it simmer for 5 minutes.
Shut the heat off and let the whole thing cool completely, about an hour or so, letting the zest and verbena steep in the syrup.
Strain the syrup into a large pitcher, pressing it lightly to make sure you extract every last drop.
Strain the lemon juice into the pitcher, pour in the water and stir to combine.
To serve, fill your glasses with ice and a torn verbena leave or two and pour over the lemonade.