Weird grappling circumstance

[Derpyninja]

Im a druid with circle of the moon so at 10th level i can wild shape into an air, fire, earth or water elemental. Before i wild shape i cast spike growth in an area, then turn into an air alemental and grapple a creature. If i were to drag that creature through the spike growth, would i also take the damage? Or is there a way to drag them without taking damage?

[Quoz]

Spike growth makes an effect on the ground. If you are flying, you are not on the ground. You can drag a grappled creature through the area without being injured by it.

This would also work for any other creature with a fly speed or other means of flight/levitation, or for other areas or obstacles that deal damage based on movement through them (though most others are limited to once per turn to prevent forces movement abuse)