Wash apples and celery thoroughly. Using a juicer, squeeze the juice from them and a circle of lemon.
Cut the cucumber into medium pieces and place in a blender bowl. Remove the tarragon leaves from the sprig, add to the cucumbers.
Pour in the squeezed juice, add 5-6 large ice cubes and beat until smooth.
Pour into tall glasses, sprinkle with lime zest and serve.