Put the prepared rose hips, water, and lemon juice in a blender; blend until smooth, about 15 seconds. Small bits of rose hips skin are okay. Gradually add the sugar while blender is running. Blend until sugar is dissolved, about 30 seconds or so.
Stir the pectin into 3/4 cup water in a saucepan. Bring to a boil; boil hard for about 1 minute. Slowly pour into the rose hip mixture; blend for about 30 seconds.
Pour into small containers with lids. Store in the refrigerator. Jam that is not used within a few weeks can be stored in the freezer for up to a year.
