One of the great things about grow bags is that they do not need drainage holes. The fabric material allows water to drain out of the bottom and sides of the bag. In fact, they drain so well that your plants may dry out quicker than if they were planted in a traditional container. You’ll want to keep tabs on weight of the bag, as well as the soil to ensure your plants are staying hydrated. It's better to place the bag on a grassy surface as opposed to solid surface. This allows the plant to absorb moisture from the ground (but can also kill the grass).