1 bunch mint sprigs, plus more for garnish
1 cup white rum
1/2 cup strawberry syrup (such as Torani®)
2 cups chilled club soda
6 cups ice cubes
Sugar for rimming glasses (optional)
6 strawberries, for garnish
Juice 4 limes, yielding about 1/2 cup juice, and cut remaining lime into 6 wedges.
Grasp mint sprig stems and slap leaves against a work surface to help release their oil; transfer to a sturdy glass pitcher. Stir in lime juice, rum, and strawberry syrup. Add club soda.
Spread 1/4 to 1/2 inch sugar on a small, shallow plate. Run a lime wedge around the rim of each glass, then dip glass into sugar. Fill with ice. Pour in mojito mixture. Garnish with mint sprigs and strawberries.