Wash the apple, spinach, celery, and ginger under cold water to remove dirt or debris.
Cut the apple into chunks, ensuring the core is removed.
Chop the celery stalk into smaller pieces.
Peel and slice the ginger root.
Add apple chunks, baby spinach, celery pieces, sliced ginger, and coconut water in a blender.
Blend in a high-speed blender until you achieve a smooth consistency, and everything is well combined (about 1-2 minutes). If necessary, add more coconut water to reach your desired consistency.
Taste the smoothie and adjust the sweetness or flavor by adding more apple or ginger if desired.
Once blended to your liking, pour the smoothie into a glass and serve immediately.
If you prefer your smoothie chilled or thicker, add ice cubes to the blender and the other ingredients before blending. Adjust the quantity of ice cubes based on your preference for temperature and texture.