In a small pot, warm your orange juice on medium heat until it starts to steam but not boil.
In a small glass dish, add gelatin and then 1-2 tbsp of warmed OJ to premelt the gelatin.
Add into the pot and stir until dissolved completely.
In your blender, add strawberries, orange, spinach if you choose, and the gelatin-OJ mixture. Blend until smooth.
Pour into your popsicle molds and freeze.