In a high-speed blender add plums, ½ cup sugar, and honey. Taste and add additional sugar (or honey) if desired.
Let sit for about 25 minutes to macerate before proceeding.
Add lemon juice blend until smooth.
Transfer the mixture to a freezer safe container and place in freezer for 2-3 hours before serving, stirring every 30 minutes. The stirring is necessary to prevent it from becoming one large fruity ice cube.