Chop up the strawberries into small chunks then add all the berries into a saucepan.
Stir the sugar into the berries with the lemon juice, then let it sit 10 min. Then bring the mixture to a boil, and let it cook 10-15 min until it becomes thickened.
Immediately pour into mason jars. Seal tightly and let cool. You don’t need to use pectin because it makes the cooking process finicky. For longer preservation, boil mason jars or pull them straight from a hot dishwasher just before adding the jam. When the lids seal, the jam can be used anytime within the following 6 months.