Place berries and sugar in a medium non-stick saucepan, and bring to a simmer, stirring frequently. Cook for 5 minutes. Pour cooked berries and syrup into a colander resting over a large bowl. Allow the berry syrup to drain. Return the syrup to the pan, and bring to a boil over medium-high heat. Reduce heat to medium, and reduce the syrup until thickened, about 20 minutes.
Return berries and any additional juice to the pan, add the lavender blossoms, and bring to a simmer for about 15 minutes, until desired consistency is reached.
Pour into a squeaky clean jar, and refrigerate up to 3 weeks, or process for canning in a water bath.