in a large saucepan combine fresh strawberries, brown sugar, and water. cook and stir over medium heat until sugar dissolves.
using a vegetable peeler, remove strips of peel from lemons (should have 1/2 a cup). add strips of lemon peel, lemon juice and rosemary to mixture in saucepan. bring mixture just to boiling, stirring occasionally. remove from heat, cover, cool to room temperature.
press mixture through a fine mesh sieve, discard solids (you should have about 1 quart syrup). to serve, fill glass with ice. to each glass ad 1/2 cup iced tea and syrup to taste (about 1/2 cup). garnish with fresh strawberries.