Your Pampas Grass may need a few days out of the shipping box to fluff up and restore its natural volume. To speed this process up, take your pampas outside and give it a light shake/twist. Then, place your pampas in the direct sunlight. The more sun your pampas gets, the more it will restore its natural volume .
Pampas Grass is a dried flower & does not require water, so there's no need to ever water your Pampas Grass.