Combine the sugar and 1 cup water in a small saucepan over medium heat. Stir until the sugar completely dissolves, then bring the mixture just to a gentle simmer without aggressively boiling it.

Remove the saucepan from the heat and add the dried culinary lavender. Cover the pan and let the lavender steep for 10 to 20 minutes.

Strain the syrup through a fine-mesh sieve to remove every piece of lavender. Let the strained syrup cool to room temperature before mixing the lemonade.

Roll the Meyer lemons firmly on the counter, then juice them at room temperature for better extraction. Strain the juice to remove seeds and excess pulp.

Pour the lemon juice, 4 cups cold water, and cooled lavender syrup into a pitcher. Stir thoroughly so the floral syrup and citrus are evenly distributed.

Taste the lemonade and adjust it if needed by adding more cold water if it is too strong, more syrup if it is too tart, or a little additional lemon juice for brightness. Refrigerate for at least 1 hour, then serve over ice with optional garnishes.