Step 1: Cut the seedless watermelon into approximately 1-inch cubes. If your watermelon has seeds, remove as many as possible.
Step 2: Place the cubed watermelon into a blender. Add the fresh lime juice. If desired, add 1 tablespoon of honey or agave nectar.
Step 3: Blend the mixture until it is completely smooth. You may need to stop and scrape down the sides of the blender to ensure everything is incorporated.
Step 4: Taste the blended watermelon mixture. If it's not sweet enough for your preference, add another tablespoon of honey or agave nectar and blend again. Keep in mind that flavors are slightly dulled when frozen.
Step 5: For an extra smooth popsicle, strain the mixture through a fine-mesh sieve into a pitcher or a large measuring cup. This step removes any remaining pulp or tiny fibers.
Step 6: Carefully pour the watermelon mixture into your popsicle molds, leaving about 1/4 inch of space at the top to allow for expansion during freezing.
Step 7: Insert popsicle sticks into the molds. Place the filled molds in the freezer.
Step 8: Freeze for at least 4-6 hours, or preferably overnight, until the popsicles are completely solid.
Step 9: To unmold, briefly run the popsicle molds under warm water for 15-20 seconds to loosen the popsicles. Gently pull them out. Serve immediately and enjoy your homemade watermelon popsicle recipes!