During the early days of a bamboo planting, it's worth giving them a bit of extra attention.
Until roots have grown into the surrounding soil, your bamboo can only access moisture in the original root zone. Ensure that water is directed at that area and allowed to soak in.
Once established, a matter of weeks in warmer weather, your bamboo's away.
After that, it's a matter of water and food.
Please see our page on Bamboo Care.