The greens rush is pouring into natural-food retailers as whole-food nutritional powders jockey to become known as the most nutritious product. Some are single-ingredient formulations such as kale or carrots. Others are the kitchen-sink approach. What other optimal nutrients and bioactives can be put into powders? There are many products available, and innovators continue to flood into the space, but no one single company dominates yet. Here are five of our favorite things.